Frequently Asked Questions: Mapping of U.S. Ocean and Coastal Waters

Frequently Asked Questions: Mapping of U.S. Ocean and Coastal Waters

Frequently Asked Questions: Mapping of U.S.
July 11, 2023
Ocean and Coastal Waters
Caitlin Keating-Bitonti,
Ocean and coastal mapping involves activities that collect data and information about the
Coordinator
underwater terrain (i.e., seafloor or lakebed). These data and information may be used to support
Analyst in Natural
marine-based economies, enhance homeland security, and protect and restore the marine
Resources Policy
environment. As of January 2023, approximately 50% of the terrain beneath U.S. coastal, ocean,

and Great Lakes waters remains unmapped.
Nicole T. Carter
Specialist in Natural
For more than a century, Congress has directed multiple federal agencies, including the National
Resources Policy
Oceanic and Atmospheric Administration (NOAA), U.S. Geological Survey (USGS), Bureau of

Ocean Energy Management, U.S. Army Corps of Engineers, and others, to support and complete
ocean and coastal mapping of the terrain beneath U.S. waters. Congress has provided direction
Laura B. Comay
Specialist in Natural
through the Ocean and Coastal Mapping Integration Act of 2009 (P.L. 111-11) and the James M.
Resources Policy
Inhofe National Defense Authorization Act for Fiscal Year 2023 (Division J, Title CIII, P.L. 117-

263), among other authorizing laws, as well as through appropriations laws and accompanying
explanatory language. In addition, executive actions have encouraged federal ocean and coastal
Christopher R. Field
mapping efforts, especially efforts to map the terrain beneath certain U.S. ocean and coastal
Analyst in Natural
waters that are least mapped (e.g., off the coast of Alaska). One such executive action (Executive
Resources Policy
Order 13840) established the Ocean Policy Committee, an interagency body that helps guide

federal ocean policy; the Ocean Policy Committee was codified by the William M. (Mac)
Eva Lipiec
Thornberry National Defense Authorization Act for Fiscal Year 2021 (Title X, Subtitle E, P.L.
Analyst in Natural
116-283). In 2020, the Ocean Policy Committee’s Ocean Science and Technology Subcommittee
Resources Policy
developed the National Strategy for Mapping, Exploring, and Characterizing the U.S. Exclusive

Economic Zone (EEZ), which identified several goals for federal ocean and coastal (including
the Great Lakes) mapping activities. This strategy is commonly known as the NOMEC (National
Linda R. Rowan
Ocean Mapping, Exploration, and Characterization) Strategy.
Analyst in Natural
Resources and Earth
Sciences
Goals of the NOMEC Strategy include mapping the terrain beneath certain ocean and coastal

areas by 2030 and 2040. These timeframes also apply to mapping the lakebeds of the Great Lakes
even though this lake system is neither part of the U.S. EEZ nor marine. To help achieve these

goals, the NOMEC Strategy recommended the creation of the NOMEC Council, which includes
membership from 11 federal agencies and is led by NOAA and the USGS. The council was established in 2020 and oversees
two interagency working groups (IWGs): the IWG on Ocean and Coastal Mapping and the IWG on Ocean Characterization
and Exploration. Together, the NOMEC Council and these two IWGs coordinate ocean and coastal mapping activities across
several U.S. departments and agencies. Since the establishment of the NOMEC Council, certain federal agencies and their
partners have prioritized mapping the entire U.S. ocean and coastal areas, including the Great Lakes, through the collection of
modern bathymetric data—the depth of the underwater terrain relative to the surface water level as collected by LiDAR or
sonar instruments. The seafloor surrounding Alaska and the lakebeds of the Great Lakes remain the least mapped areas (by
percentage) of U.S. ocean and coastal waters.
Congress influences U.S. ocean and coastal mapping efforts by authorizing or appropriating funding to specific agencies to
engage in or support mapping activities. Congress also has directed and funded agencies to focus mapping efforts on specific
states and regions, such as offshore Alaska and the Great Lakes system. Congress may wish to continue prioritizing specific
ocean and coastal mapping efforts through appropriations. Congress also may consider approaches to overcome stakeholder-
identified U.S. ocean and coastal mapping challenges by directing federal agencies to standardize technical protocols for
acquiring bathymetric data and providing additional support for collaboration between public and private mapping efforts and
data sharing, among others.
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Contents
Introduction ..................................................................................................................................... 1
What Are Some Benefits of Ocean and Coastal Water Mapping? .................................................. 1
What Is Ocean and Coastal Mapping? ............................................................................................ 2
What Are U.S. Goals for Ocean and Coastal Mapping? ................................................................. 4
How Much of U.S. Ocean and Coastal Waters Are Mapped? ......................................................... 5
How Are Ocean and Coastal Waters Mapped? ................................................................................ 7
How Are U.S. Bathymetric Data Coordinated and Made Available? .............................................. 9
What Are Some Challenges to Ocean and Coastal Water Mapping Efforts? ................................ 10
Where Are U.S. Ocean and Coastal Waters the Least Mapped? ................................................... 12
Ocean and Coastal Waters of Alaska ....................................................................................... 13
Lakebeds of the Great Lakes ................................................................................................... 13
How Have Congress and the President Directed Federal Agencies to Support Ocean and
Coastal Mapping Efforts? ........................................................................................................... 14
How Are Federal Ocean and Coastal Mapping Efforts Coordinated? ........................................... 19
How Are Nonfederal Partners and Crowdsourced Data Involved in Federal Ocean and
Coastal Mapping Efforts? ........................................................................................................... 21

Figures
Figure 1. Bathymetric Map of Offshore Washington State ............................................................. 3
Figure 2. Relationship Between Mapping, Exploration, and Characterization ............................... 4
Figure 3. Unmapped U.S. Coastal, Ocean, and Great Lakes Waters in January 2023 .................... 7
Figure 4. Selected Assets Equipped with Multibeam Sonar and LiDAR Instruments .................... 8
Figure 5. Structure of the Interagency Committees, Councils, and Working Groups with
Primary Mapping, Exploration, and Characterization Responsibilities ..................................... 20

Tables
Table 1. Percentage of Unmapped U.S. Coastal, Ocean, and Great Lakes Waters .......................... 6
Table 2. Selected U.S.-Owned Oceanographic Research Vessels .................................................. 11
Table 3. Chronology of Selected Federal Ocean and Coastal Mapping-Related Authorities ........ 14
Table 4. Selected Federal Department and Agencies Involved in U.S. Ocean and Coastal
Mapping ..................................................................................................................................... 16

Table A-1. Selected Federal Departments, Agencies, and Offices Involved in U.S. Ocean
and Coastal Mapping .................................................................................................................. 23

Appendixes
Appendix. ...................................................................................................................................... 23
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Contacts
Author Information ........................................................................................................................ 24

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Frequently Asked Questions: Mapping of U.S. Ocean and Coastal Waters

Introduction
Ocean and coastal mapping involves activities that collect data and information about the
underwater terrain (i.e., seafloor or lakebed). Ocean and coastal mapping provides useful
information for maritime commerce, seafood production, commercial and recreational fisheries,
offshore energy production, marine tourism and recreation, environmental protection and
restoration, national and homeland security, and other activities.1 For more than a century,
Congress has shown interest in ocean and coastal mapping activities. Congress has directed and
funded certain federal departments and agencies to collect relevant data and information about
U.S. ocean and coastal waters. Executive actions also have encouraged federal agencies to map
the terrain beneath certain U.S. ocean and coastal waters. One such executive action, Executive
Order (E.O.) 13840, established the Ocean Policy Committee, an interagency body that helps
guide federal ocean policy.2 Several federal departments and agencies that participate in ocean
and coastal mapping activities aim to completely map the terrain beneath U.S. ocean waters by
2030 and the terrain beneath U.S. coastal waters by 2040. These goals were identified by the
Ocean Policy Committee’s Ocean Science and Technology Subcommittee in the National
Strategy for Mapping, Exploring, and Characterizing the U.S. Exclusive Economic Zone (EEZ). 3
This strategy is commonly known as the NOMEC (National Ocean Mapping, Exploration and
Characterization) Strategy. This report answers questions about ocean and coastal mapping
activities and relevant U.S. mapping efforts.
What Are Some Benefits of Ocean and Coastal Water
Mapping?
Various stakeholders have cited benefits of ocean and coastal water mapping. For example,
Congress, in its 2022 amendments to several ocean and coastal mapping laws, noted that
“mapping, exploration, and characterization of the ocean provides basic, essential information to
protect and restore the marine environment, stimulate economic activity, and provide security for
the United States.”4 According to a group of federal agencies directed to support ocean and
coastal mapping, “Ocean mapping, exploration, and characterization (MEC) is necessary to
advance maritime commerce, domestic seafood production, healthy and sustainable fisheries,

1 Ocean Policy Committee, Ocean Science and Technology Subcommittee, National Ocean Mapping, Exploration, and
Characterization (NOMEC) Council, Implementation Plan for the National Strategy for Ocean Mapping, Exploring,
and Characterizing the United States Exclusive Economic Zone, January 2021, p. 3. Hereinafter referred to as NOMEC
Council, Implementation Plan.
2 The Ocean Policy Committee was created on January 19, 2018 by Executive Order 13840 “Regarding the Ocean
Policy to Advance the Economic, Security, and Environmental Interests of the United States” and was later codified by
the William M. (Mac) Thornberry National Defense Authorization Act for Fiscal Year 2021 (P.L. 116-283), Title X,
Subtitle E (Executive Order 13840, “Ocean Policy to Advance the Economic, Security, and Environmental Interests of
the United States,” 86 Federal Register 29431, June 19, 2018).
3 The Ocean Science and Technology Subcommittee of the Ocean Policy Committee developed the National Strategy
for Mapping, Exploring, and Characterizing the United States Exclusive Economic Zone pursuant to 2019 presidential
memorandum (Executive Office of the President, “Ocean Mapping of the United States Exclusive Economic Zone and
the Shoreline and Nearshore of Alaska,” 84 Federal Register 64699, November 22, 2019 [hereinafter referred to as
Presidential Memorandum on Ocean Mapping of the U.S. EEZ, 2019]).
4 James M. Inhofe National Defense Authorization Act for Fiscal Year 2023 (P.L. 117-263), Division J, Title CIII,
§10301(6).
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coastal resilience, energy production, tourism and recreation, environmental protection,
conservation, national and homeland security, and other interests.”5
Ocean and coastal mapping can aid in a range of activities, including
• exploring for and extracting offshore oil and gas and seabed minerals,6
• siting telecommunication and offshore wind turbine-related cables,7
• identifying navigational hazards for recreational boating and commercial
shipping,8
• determining the extent of the U.S. continental shelf,9
• assessing marine geohazards,10 and
• protecting marine environments and ecosystems of interest.11
What Is Ocean and Coastal Mapping?
Mapping of ocean and coastal waters involves activities that collect data and information about
the underwater terrain (i.e., seafloor or lakebed).12 In general, U.S. ocean mapping involves
mapping the seafloor beneath the U.S. EEZ, whereas U.S. coastal mapping involves mapping the
seafloor beneath state waters (at least 3 nautical miles from the shoreline).13 The James M. Inhofe
National Defense Authorization Act for Fiscal Year 2023 (P.L. 117-263) addressed national ocean
exploration; specifically, Division J, Title CIII, of the act defined mapping as “activities that
provide comprehensive data and information needed to understand seafloor characteristics, such
as depth, topography, bottom type, sediment composition and distribution, underlying geologic
structure, and benthic flora and fauna.”14
Section 12208 of the Ocean and Coastal Mapping Integration Act of 2009 (Title XII, Part II,
Subtitle B, of P.L. 111-11), as amended, defined ocean and coastal mapping as

5 NOMEC Council, Implementation Plan, p. 3. For more on the NOMEC Council, see “How Have Congress and the
President Directed Federal Agencies to Support Ocean and Coastal Mapping Efforts?”
6 Bureau of Ocean Energy Management (BOEM), “BOEM Mapping Resources,” at https://www.boem.gov/
environment/boem-mapping-resources. For more information on applications of bathymetric data related to nonliving
natural resources, see CRS Report R47021, Federal Involvement in Ocean-Based Research and Development, by
Caitlin Keating-Bitonti.
7 National Oceanic and Atmospheric Administration (NOAA), “Why Map the Seafloor? To Keep Us—and Natural
Resources—Safe,” at https://oceanexplorer.noaa.gov/world-oceans-day-2015/why-map-the-seafloor-to-keep-us-and-
natural-resources-safe.html.
8 Ibid.
9 For more information about the extent of the U.S. continental shelf, see CRS Report R41153, Changes in the Arctic:
Background and Issues for Congress, coordinated by Ronald O'Rourke.
10 U.S. Geological Survey (USGS), “Marine Geohazards,” at https://www.usgs.gov/science/science-explorer/ocean/
marine-geohazards.
11 NOAA, “How Is Bathymetric Data Used?,” at https://oceanservice.noaa.gov/facts/bathyuses.html.
12 Congress included the Great Lakes as part of a federal ocean and coastal mapping plan (33 U.S.C. §3501).
13 The U.S. exclusive economic zone is the ocean area located generally between 3 and 200 nautical miles from the
shoreline. White House, “Proclamation 5030: Exclusive Economic Zone of the United States of America,” 48 Federal
Register 10605, March 10, 1983.
14 The National Ocean Exploration Title of the James M. Inhofe National Defense Authorization Act for Fiscal Year
2023 modified Section 12001 of the Omnibus Public Land Management Act of 2009 (33 U.S.C. §3401) by inserting
this definition of mapping. It also applies the definition to map (P.L. 117-263, Division J, Title CIII, §10305(h)).
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the acquisition, processing, management, maintenance, interpretation, certification, and
dissemination of physical, biological, geological, chemical, and archaeological
characteristics and boundaries of ocean and coastal areas, resources, and sea beds through
the use of acoustics, satellites, aerial photogrammetry, light and imaging, direct sampling,
and other mapping technologies.15
One aspect of mapping underwater terrain is the collection of data regarding the ocean or lake
depth relative to the surface water level, known as bathymetric data.16 Similar to topographic
maps on land, bathymetric maps reveal three-dimensional features of the underwater terrain
(Figure 1).
Figure 1. Bathymetric Map of Offshore Washington State

Source: U.S. Geological Survey, Pacific Coastal and Marine Science Center, “Bathymetric Map of Offshore
Washington,” at https://www.usgs.gov/media/images/bathymetric-map-offshore-washington.
Notes: This bathymetric map reveals the seafloor features, including submarine canyons, offshore Washington
state. The red color represents shallower water depths, and the blue color represents deeper water depths. The
grayscale area at the top of the map is the relief of the land (i.e., topography); white represents lower elevation,
and black represents higher elevation.
Bathymetric maps can inform site selection for exploration and characterization (Figure 2).17
The James M. Inhofe National Defense Authorization Act for Fiscal Year 2023 defined
exploration as “activities that provide (A) a multidisciplinary view of an unknown or poorly
understood area of the seafloor, sub-bottom, or water column; and (B) an initial assessment of the
physical, chemical, geological, biological, archeological, or other characteristics of such an
area.”18 The act defined characterization as “activities that provide comprehensive data and
interpretations for a specific area of interest of the sea floor, sub-bottom, water column, or
hydrologic features, including water masses and currents, in direct support of specific research,
environmental protection, resource management, policy making, or applied mission objective.”

15 §10307(g) of the National Ocean Exploration Act (P.L. 117-263, Division J, Title CIII) amended the definition of
ocean and coastal mapping by replacing “processing, and management” with “processing, management, maintenance,
interpretation, certification, and dissemination.”
16 NOAA, “What Is Bathymetry?,” at https://oceanservice.noaa.gov/facts/bathymetry.html.
17 NOMEC Council, Implementation Plan, p. 7.
18 P.L. 117-263, Division J, Title CIII.
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The focus of this report is on ocean and coastal mapping activities.
Figure 2. Relationship Between Mapping, Exploration, and Characterization

Source: Congressional Research Service (CRS); Ocean Science and Technology Subcommittee and Ocean
Policy Committee, National Ocean Mapping, Exploration, and Characterization Council, Implementation Plan for
the National Strategy for Ocean Mapping, Exploring, and Characterizing the United States Exclusive Economic Zone,
January 2021, p. 6.
Note: Ocean and coastal mapping can inform both exploration and characterization activities. Exploration can
inform in-depth characterization.
What Are U.S. Goals for Ocean and Coastal
Mapping?
In June 2020, the Ocean Science and Technology Subcommittee of the Ocean Policy Committee
announced the NOMEC Strategy (for more information about federal committees, councils, and
interagency working groups focused on ocean and coastal mapping, see “How Are Federal Ocean
and Coastal Mapping Efforts Coordinated?”). The NOMEC Strategy established five goals.19
1. Coordinate interagency efforts and resources to map, explore, and characterize
the U.S. EEZ
2. Map the U.S. EEZ
3. Explore and characterize priority areas of the U.S. EEZ20
4. Develop and mature new and emerging science and technologies to map, explore,
and characterize the U.S. EEZ
5. Build public and private partnerships beyond federal agencies to map, explore,
and characterize the U.S. EEZ
The NOMEC Strategy also provides deadlines to meet certain goals. For example, the strategy
aims to map the terrain beneath certain U.S. ocean waters (water depths greater than 40 meters
[m], or 43.7 yards) by 2030.21 Water depths greater than 40 m within the U.S. EEZ represent
approximately 90% of the U.S. EEZ area.22 The strategy aims to map the terrain beneath U.S.
coastal waters (water depths less than 40 m), which includes state waters and some areas of the
U.S. EEZ, by 2040.23 According to the NOMEC Strategy, mapping U.S. coastal waters is

19 Ocean Policy Committee, Ocean Science and Technology Subcommittee, National Strategy for Mapping, Exploring,
and Characterizing the United States Exclusive Economic Zone, June 9, 2020, p. 2. Hereinafter referred to as NOMEC
Strategy, 2020.
20 U.S. exploration and characterization activities are focused on waters 40 meters and deeper. NOMEC Council,
Implementation Plan, p. 15.
21 NOMEC Strategy, 2020, p. 9.
22 Ibid.
23 Ibid.
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estimated to require two-thirds of the total level of effort required to map the entire U.S. EEZ.24
Mapping of the lakebeds of the Great Lakes is also included in the NOMEC Strategy even though
the Great Lakes are not a part of the U.S. EEZ.25
The NOMEC Strategy’s goals to map the terrain beneath U.S. ocean and coastal waters may align
with larger global goals. For instance, in 2022, the National Oceanic and Atmospheric
Administration (NOAA) Administrator signed a memorandum of understanding that formalized
U.S. participation in the Nippon Foundation-General Bathymetric Chart of the Oceans Seabed
2030 Project (Seabed 2030).26 Seabed 2030 aims to map the entire global seafloor by 2030.27
How Much of U.S. Ocean and Coastal Waters Are
Mapped?
NOAA periodically analyzes available modern (post-196028) bathymetric data to evaluate U.S.
ocean and coastal mapping progress.29 NOAA completed its first such analysis in 2017.
Following a 2019 presidential memorandum entitled “Ocean Mapping of the United States
Exclusive Economic Zone and the Shoreline and Nearshore Alaska” (hereinafter referred to as the
2019 presidential memorandum on ocean mapping of the U.S. EEZ),30 NOAA has released an
annual progress report of unmapped U.S. waters (i.e., ocean and coastal waters and the Great
Lakes).31 These annual progress reports quantify the area of U.S. waters mapped during the
previous year and present this information as the percentage of U.S. waters (i.e., ocean and
coastal waters and the Great Lakes) unmapped (Table 1), also known as the “gap analysis.”32 For
example, the annual progress report published in January 2023 revealed that 50% of U.S. coastal,
ocean, and Great Lakes waters were unmapped as of 2022 (Figure 3).33 For this dataset,
unmapped areas can mean that “either no direct measurements of the seafloor have been acquired
over these areas or data has been collected and not shared for broader use” (for more on data
acquisition, see “How Are U.S. Bathymetric Data Coordinated and Made Available?”).34
According to NOAA, a specified area of the seafloor or lakebed of the Great Lakes is considered

24 Ibid.
25 The Great Lakes are considered internal waters of the United States. See Article 8 of the United Nations Framework
Convention on the Law of the Sea (United Nations, "United Nations Convention on the Law of the Sea of 10 December
1982, Overview and full text,"
at https://www.un.org/depts/los/convention_agreements/convention_overview_convention.htm.
26 NOAA, “Seabed 2030,” June 29, 2022, at https://oceanservice.noaa.gov/news/jun22/seabed-2030.html.
27 The Nippon Foundation—General Bathymetric Chart of the Oceans Seabed 2030 Project, “About the Seabed 2030
Project,” at https://seabed2030.org/about-us.
28 Post-1960 refers when the U.S. Navy declassified multibeam sonar technology for civil use (see Hydro International,
“A Note on Fifty Years of Multi-beam,” May 22, 2013, at https://www.hydro-international.com/content/article/a-note-
on-fifty-years-of-multi-beam).
29 NOAA, “U.S. Bathymetric Coverage and Gap Analysis,” at https://iocm.noaa.gov/seabed-2030-bathymetry.html
(hereinafter referred to as NOAA, Bathymetric Gap Analysis) and NOAA, “United States Bathymetric Gap Analysis,”
at https://noaa.maps.arcgis.com/home/item.html?id=4d7d925fc96d47d9ace970dd5040df0a.
30 Presidential Memorandum on Ocean Mapping of the U.S. EEZ, 2019.
31 The first annual progress report of unmapped U.S. waters was published in January 2020 (NOAA, “Progress Report:
Unmapped U.S. Waters,” March 2020, at https://iocm.noaa.gov/seabed-2030/mapping-progress-report2020.pdf).
32 NOAA, Bathymetric Gap Analysis.
33 NOAA, “Progress Report: Unmapped U.S. Waters,” March 2023, at https://iocm.noaa.gov/documents/mapping-
progress-report2023.pdf.
34 NOAA, “Status of Seafloor Mapping Within U.S. Waters,” at https://iocm.noaa.gov/seabed-2030-status.html.
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mapped when at least one sonar (sound navigation and ranging) or LiDAR (Light Detection and
Ranging) measurement has been collected for that area (for more on sonar and LiDAR, see “How
Are Ocean and Coastal Waters Mapped?”).35
Table 1. Percentage of Unmapped U.S. Coastal, Ocean, and Great Lakes Waters
Total
Percentage Unmapped
Area
Region
(snm)
2017
2018
2019
2020
2021
2022
All U.S.
3,590,500
59%
57%
54%
53%
52%
50%
Waters
Atlantic
472,200
49%
48%
43%
41%
40%
37%
and Gulf of
Mexico
Caribbean
61,600
45%
44%
42%
43%a
42%
30%
(USVI, PR)
Alaska
1,080,200
74%
73%
72%
72%
69%
66%
Pacific (CA, 239,700
29%
29%
24%
22%
20%
19%
OR, WA)
Hawaii and
1,691,700
55%
53%
50%
49%
48%
47%
Pacific
Remote
Islands
Great
45,100b
96%
96%
95%
95%
93%
92%
Lakes
Source: CRS; National Oceanic and Atmospheric Administration, “Progress Report: Unmapped U.S. Waters,”
March 2020, at https://iocm.noaa.gov/seabed-2030/mapping-progress-report2020.pdf; March 2021, at
https://iocm.noaa.gov/seabed-2030/mapping-progress-report2021.pdf; March 2022, at https://iocm.noaa.gov/
documents/mapping-progress-report2022.pdf; and March 2023, at https://iocm.noaa.gov/documents/mapping-
progress-report2023.pdf.
Notes: CA = California; OR = Oregon; PR = Puerto Rico; snm = square nautical miles; USVI = U.S. Virgin
Islands; WA = Washington. The Pacific Remote Islands include the Commonwealth of the Northern Mariana
Islands, Guam, American Samoa, Wake Island, Johnston Atol , Howland Island, Baker Island, Kingman Reef, and
Palmyra Atol .
a. The Caribbean “lost” 600 snm, equating to 1%, of mapping area in 2020 due to a minor correction to
remove known bad/poor bathymetric data from the calculation
b. In 2021, the total area of the Great Lakes lakebeds was adjusted from 46,600 snm to 45,100 snm due to the
removal of some land features.

35 NOAA considers a specific area (i.e., a grid cell measuring 100x100 meters) of the seafloor minimally mapped if the
area contains at least one sonar or LiDAR measurement. NOAA refers to a grid cell that has three or more
measurements as better mapped. NOAA, “U.S. Bathymetric Coverage and Gap Analysis,” at https://iocm.noaa.gov/
seabed-2030-bathymetry.html.
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Figure 3. Unmapped U.S. Coastal, Ocean, and Great Lakes Waters in January 2023

Source: Modified by CRS; National Oceanic and Atmospheric Administration (NOAA), “Progress Report:
Unmapped U.S. Waters,” March 2023, at https://iocm.noaa.gov/documents/mapping-progress-report2023.pdf.
Notes: A January 2023 NOAA analysis estimated that 50% of U.S. Coastal, Ocean, and Great Lakes waters are
unmapped (red areas). The seaward extent of the U.S. exclusive economic zone is denoted by the yellow line,
and the Arctic boundary is denoted by the navy blue line. The Arctic Research and Policy Act of 1984 (P.L. 98-
373 ) defined the U.S. Arctic as the “territory north and west of the boundary formed by the Porcupine, Yukon,
and Kuskokwim Rivers; all contiguous seas, including the Arctic Ocean and the Beaufort, Bering, and Chukchi
Seas; and the Aleutian chain.”
How Are Ocean and Coastal Waters Mapped?
Underwater terrain is mapped using bathymetric data.36 Federal agencies, academic institutions,
and private companies collect bathymetric data using sonar or LiDAR instruments (for more
information on the involvement of federal agencies and departments, see “How Are Federal
Ocean and Coastal Mapping Efforts Coordinated?”). In general, sonar instruments map the
seafloor beneath the surface of the ocean and LiDAR instruments map the seafloor beneath
coastal waters (up to a water depth of 80 m); sonar and LiDAR instruments also are used to map
the lakebeds of the Great Lakes and other lakes (Figure 4). The NOMEC Strategy’s goal to map
U.S. waters with a depth greater than 40 meters by 2030 would rely primarily on data collected
via sonar instruments; whereas, goal to map U.S. waters with a depth less than 40 meters by 2040
would rely on data collected via sonar and LiDAR instruments.

36 For more information about oceanographic data and approaches for ocean mapping and characterization, see CRS
Report R47021, Federal Involvement in Ocean-Based Research and Development, by Caitlin Keating-Bitonti.
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Figure 4. Selected Assets Equipped with Multibeam Sonar and LiDAR Instruments

Source: CRS; National Oceanic and Atmospheric Administration, “Progress Report: Unmapped U.S. Waters,”
March 2023, at https://iocm.noaa.gov/documents/mapping-progress-report2023.pdf.
Notes: The underwater terrain of the shallow coastal areas is generally mapped using aircraft and satellites
equipped with LiDAR instruments. LiDAR instruments can col ect bathymetric data in certain waters up to 80
meters water depth. Small boats equipped with multibeam sonar instruments can be used to map the
underwater terrain of shallow coastal areas but may be limited by navigation concerns. Large vessels equipped
with multibeam sonar technology are best suited for mapping the deep underwater terrain beneath open waters
free of navigation hazards.
Sonar data provide information about the depths and shapes of the underwater terrain, and these
data are used to create bathymetric maps. Sonar systems send sound pulses from a sensor—called
a transducer array—attached to the bottom of a ship, or another water vehicle, to the underwater
terrain. The amount of time it takes for sound pulses to leave the array, bounce off the underwater
terrain, and return to the array is used to calculate the distance to the seafloor (i.e., water depth).37
The faster a sound pulse returns to the array, the shallower the water depth. Commonly used sonar
systems are single beam sonars, which use a single vertical sound pulse to collect data of the
underwater terrain directly beneath the ship, and multibeam sonars, which use multiple splayed
sound pulses to collect data of the underwater terrain directly beneath and out to each side of the
ship.38
In addition to providing information about water depth, multibeam sonars can collect backscatter
measurements, which correspond to the return beam’s intensity. The return beam’s intensity
provides information about the seafloor’s composition. For example, a mud surface absorbs most
of the sound pulse, returning a weak signal to the receiver, whereas a rocky surface absorbs little
of the sound pulse, returning a strong signal.39

37 NOMEC Council and the Interagency Working Group on Ocean and Coastal Mapping (IWG-OCM), “Draft Standard
Ocean Mapping Protocol,” February 2023, at https://iocm.noaa.gov/standards/
Standard_Ocean_Mapping_Protocol_draft_Feb2023.pdf, p. 31. Hereinafter referred to as NOMEC and IWG-OCM,
Draft Standard Ocean Mapping Protocol.
38 Ibid.
39 Ibid, pp. 31-32, and NOAA, “Sea Floor Mapping,” at https://oceanexplorer.noaa.gov/explorations/lewis_clark01/
background/seafloormapping/seafloormapping.html.
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Coastal waters can be challenging and time-consuming to map, because shallow waters may be
inaccessible to oceanographic research vessels.40 Remote sensing technology can be used to
overcome some of these challenges. LiDAR is a remote sensing method commonly used on
aircraft, but some satellites are also equipped with LiDAR instruments.41 A LiDAR instrument
primarily consists of a laser emitter-receiver scanning unit and a specialized global positioning
system (GPS) unit; bathymetric LiDAR uses a laser emitting green light that penetrates through
water. Similar to sonar, the amount of time it takes pulsed laser beams to reach the underwater
terrain and return to a receiver fixed to an aircraft or satellite is used is calculate water depth.42
LiDAR is limited to relatively clear and calm coastal waters, because breaking waves or water
containing sediment, marine vegetation, and other materials reduce the laser light’s ability to
penetrate through the water.43
As directed by Congress,44 a group of federal agencies and departments, including NOAA,
developed a draft Standard Ocean Mapping Protocol, which encourages consistency in data
acquisition, stewardship, and data management for ocean and coastal mapping.45 The draft
protocol aims to address some stakeholder concerns about the lack of consistency in the types and
specifications of bathymetric data acquired by NOAA.
How Are U.S. Bathymetric Data Coordinated and
Made Available?
NOAA National Center for Environmental Information (NCEI) bathymetry holdings are the
primary source of bathymetric data.46 NCEI serves as the central repository and archive for global
single-beam and multibeam sonar bathymetry.47 Bathymetric LiDAR is archived by NCEI and
NOAA’s Digital Coast.48 NCEI bathymetric holdings are compliant with the Geospatial Data Act

40 Shallow coastal waters may present hazards for ships and, in high latitude regions, coastal waters are more prone to
freezing, thereby limiting data collection to ice-free seasons.
41 Imaging and environment-monitoring instruments on commercial satellites, such as the Maxar satellite series, can be
applied to coastal water mapping projects (Maxar, “The Power of Bathymetry Now Available in SecureWatch,” April
8, 2020, at https://blog.maxar.com/earth-intelligence/2020/the-power-of-bathymetry-now-available-in-securewatch).
Some federally owned (i.e., Landsat 8, Landsat 9, and ICESat-2) satellites are also equipped with LiDAR technology
that can be used to map coastal waters (USGS, “Satellite-Derived Bathymetry,” at https://www.usgs.gov/special-topics/
coastal-national-elevation-database-%28coned%29-applications-project/science/satellite#overview; and National
Aeronautics and Space Administration [NASA], “Sounding the Seafloor with Light,”
at https://earthobservatory.nasa.gov/images/148246/sounding-the-seafloor-with-light. For more information, see CRS
Report R46560, Landsat 9 and the Future of the Sustainable Land Imaging Program, by Anna E. Normand).
42 NOMEC and IWG-OCM, Draft Standard Ocean Mapping Protocol, p. 46.
43 Ibid, pp. 44, 46.
44 P.L. 117-263, Division J, Title CIII, §10304(i)(2)(I), and NOMEC Strategy, 2020, pp.17-18.
45 See, NOAA, “Request for Public Comment on a Draft Standard Ocean Mapping Protocol,” 88 Federal Register
11900, February 24, 2023.
46 Email correspondence with NOAA, Congressional Affairs Specialist, Office of Legislative and Intergovernmental
Affairs (OLIA), June 15, 2023.
47 Ibid. NOAA NCEI is also the repository for bathymetric grids created for the U.S. Extended Continental Shelf
Project. For more information about the U.S. Extended Continental Shelf Project, see CRS Report R41153, Changes in
the Arctic: Background and Issues for Congress, coordinated by Ronald O'Rourke.
48 See, NOAA, “Coastal Topographic LiDAR,” at https://coast.noaa.gov/digitalcoast/data/coastallidar.html.
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of 2018 (P.L. 115-254, Title VII, Subtitle F) as all of these data can be accessed and viewed
through the NOAA Bathymetric Data Viewer.49
NCEI’s bathymetric holdings include data collected by the federal government, states, academic
institutions, non-governmental institutions, the private sector, and crowdsource providers.50 To
establish a working relationship with NCEI, data providers must enter into a submission
agreement with NCEI. These data providers are required to submit their data in standardized
formats with appropriate metadata to ensure equal access and useability.51 In cases where NCEI
acquires data that are not in standardized format, NCEI may need to process data to extract
bathymetric information.52
NCEI may not share bathymetric data for several reasons. First, some data may have been
collected and cannot be shared for broader use until NCEI has processed and converted the data
into the standardized format—data processing could delay public access by a year or more.53
Second, some scientific journals require scientists to publish primary data alongside research
results, which could also delay public access to these data. Other data restrictions include
business proprietary, ownership issues, and national security concerns, among others.
What Are Some Challenges to Ocean and Coastal
Water Mapping Efforts?
The NOMEC implementation plan provides a blueprint to coordinate federal and non-
governmental efforts needed to achieve the goals of the NOMEC Strategy. During the
development of the NOMEC implementation plan, the NOMEC Council identified several
limitations to ocean and coastal water mapping. These limitations included the need to
• improve engagement with stakeholder groups to implement the NOMEC
Strategy;
• incorporate marine cultural heritage, underwater archaeology, and
paleolandscapes in ocean and coastal mapping priorities;54
• strengthen collaboration with the private sector to advance innovative
development and use of uncrewed systems (e.g., remotely operated vehicles,
drones);
• align the types and specifications of data (e.g., bathymetric resolution, time series
data, imaging) across sectors;
• manage and store data and make data accessible and usable;
• engage the next generation of hydrographers, ocean explorers, and scientists; and

49 See, NOAA, “Bathymetric Data Viewer,” at https://www.ncei.noaa.gov/maps/bathymetry/. For more information on
the Geospatial Data Act of 2018, see CRS Report R45348, The Geospatial Data Act of 2018, by Peter Folger.
50 NOAA Bathymetric Gap Analysis.
51 Email correspondence with NOAA, Congressional Affairs Specialist, Office of Legislative and Intergovernmental
Affairs (OLIA), June 15, 2023.
52 Ibid.
53 Ibid.
54 A paleolandscape is an ancient area of land that may preserve information about how people inhabited, occupied,
and used the land. For example, see NOAA, “Paleolandscapes, Paleoecology, and Cultural Heritage on the Southern
California Continental Shelf – Geophysical Mapping Phase,” at
https://oceanexplorer.noaa.gov/explorations/21paleolandscapes/welcome.html.
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• streamline the permitting process for ocean and coastal mapping activities.55
Federal ocean and coastal mapping efforts also may be limited by the availability of
oceanographic research vessels (ORVs) with mapping capability, including vessels with
partnerships with the federal government and U.S.-owned vessels (Table 2).56 Two vessels in
NOAA’s fleet, Fairweather and Rainier, are over 55 years old. The pending retirement of these
two vessels will result in the loss of 100% of NOAA’s mapping capacity in the Pacific and Arctic
Oceans.57 NOAA anticipates the forthcoming acquisition of two new replacement vessels will
allow for mapping activities to continue in the Pacific.58 Other resource considerations associated
with ORVs include staffing levels, funding (e.g., operational sea days), and competing research
projects and priorities.59
Table 2. Selected U.S.-Owned Oceanographic Research Vessels
Name
Type
Owner (Operator)
Atlantis*
Oceanographic
U.S. Navy (WHOI)
Fairweather
Hydrographic
NOAA (NOAA)
Ferdinand R. Hassler
Hydrographic
NOAA (NOAA)
Nancy Foster
Oceanographic
NOAA (NOAA)
Okeanos Explorer
Oceanographic
NOAA (NOAA)
Rainier
Hydrographic
NOAA (NOAA)
Roger Revelle*
Oceanographic
U.S. Navy (Scripps Institution of Oceanography)
Ronald H. Brown*
Oceanographic
NOAA (NOAA)
Thomas Jefferson
Hydrographic
NOAA (NOAA)
Thompson*
Oceanographic
U.S. Navy (UW School of Oceanography)
Source: CRS; National Oceanic and Atmospheric Administration (NOAA), “Observation Platforms: Vessels,” at
https://oceanexplorer.noaa.gov/technology/vessels/vessels.html; NOAA “Ship-Finder,” at
https://www.omao.noaa.gov/mo/ship-finder; University-National Oceanographic Laboratory System (UNOLS),
“UNOLS Designated Vessels,” at https://www.unols.org/ships-facilities/unols-vessels; and email correspondence
with NOAA, Congressional Affairs Specialist, Office of Legislative and Intergovernmental Affairs, April 18, 2023.
Notes: UW = University of Washington; WHOI = Woods Hole Oceanographic Institution. Asterisk (*) denotes
a UNOLS-designated vessel as part of the U.S. Academic Research Fleet.
Some have argued that ORV limitations, such as challenges associated with the vessels’ operation
in shallow coastal waters or their availability, may be overcome by the use of other technologies.
The National Aeronautics and Space Administration (NASA), NOAA, and the U.S. Army Corps
of Engineers (USACE) operate and use airborne LiDAR instruments equipped with a laser

55 NOMEC Council, Implementation Plan, Appendix A.
56 For example, while NOAA provides funding for research and mission input for Nautilus, an exploration vessel
owned and operated by the Ocean Exploration Trust, NOAA does not directly task or assign missions to this vessel
(email correspondence with NOAA, Congressional Affairs Specialist, Office of Legislative and Intergovernmental
[OLIA] Affairs, April 18, 2023). Nautilus is equipped with multibeam sonar that has been used to map the seafloor
(NOAA, “Exploration Vessel Nautilus,” at https://oceanexplorer.noaa.gov/technology/vessels/nautilus/nautilus.html).
57 NOAA, “The NOAA Fleet Plan: Building NOAA’s 21st Century Fleet,” October 31, 2016, pp. 24, 27.
58 The Consolidated Appropriations Act, 2023 provided funds to NOAA for the acquisition and construction of vessels
and aircraft (P.L. 117-328, Division B, Title I). Email correspondence with NOAA, Congressional Affairs Specialist,
OLIA, April 18, 2023.
59 Email correspondence with NOAA, Congressional Affairs Specialist, OLIA, April 18, 2023.
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emitting green light to map and chart coastal waters (up to 80 m water depth). For example, the
Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX), a multiagency effort
led by USACE, operates and uses airborne LiDAR bathymetry technology to map and chart
coastal waters worldwide.60 According to USACE, there is capacity in the JALBTCX
sensor/aircraft fleet and calendar to accommodate additional mapping activities to complement
the goals of NOMEC if funds are made available to do so.61 As another example, NASA collects
coastal bathymetric data using LiDAR and radar instruments on satellites (e.g., Ice, Cloud and
Land Elevation Satellite 2 [ICESat-2] and Surface Water and Ocean Topography [SWOT]),62 the
International Space Station,63 and aircraft.64 Such satellite instruments were not necessarily
designed primarily to collect bathymetric data, but their capabilities can be used for that purpose
and others, such as measuring surface water, ice, and forests.65
Where Are U.S. Ocean and Coastal Waters the Least
Mapped?
Federal ocean and coastal areas are not evenly mapped across the United States and its territories
(see Table 1). To help identify where U.S. mapping efforts should focus, the Interagency Working
Group on Ocean and Coastal Mapping (IWG-OCM), a federal group established under law,66
surveys ocean and coastal mapping partners and those who rely on mapping data for their priority
areas. For example, one survey asked NOAA program offices to determine which areas of the
ocean and Great Lakes they needed mapped, and why.67 The IWG-OCM reviews these surveys to
determine overlapping mapping interests to “coordinate and leverage resources where there is a
shared mapping need.”68
Two areas that have received attention for being the least mapped are the ocean and coastal
waters of Alaska and the lakebeds of the Great Lakes. Both Congress and the President have
directed specific federal agencies to map the seafloor off Alaska’s coast and the lake beds of the
Great Lakes. For example, in the explanatory statement accompanying the Consolidated
Appropriations Act, 2023 (P.L. 117-328), Congress directed NOAA to use certain funds “to
continue coordinating and implementing an interagency mapping, exploration, and
characterization strategy for the U.S. Exclusive Economic Zone, as well as the Strategy for

60 Federal agencies included in the Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) are the
U.S. Army Corps of Engineers (USACE), U.S. Naval Meteorology and Oceanography Command, NOAA, and USGS.
USACE, “About JALBTCX,” at https://jalbtcx.usace.army.mil/.
61 While the USACE owns airborne LiDAR instruments, USACE contracts for the aircraft to fly the instruments
(USACE, remote briefing to CRS, April 25, 2023). NOAA, “Integrated Ocean & Coastal Mapping, Interagency
Working Group—Ocean and Coastal Mapping,” at https://iocm.noaa.gov/about/iwg-ocm.html.
62 NASA, “Sounding the Seafloor with Light,” at https://earthobservatory.nasa.gov/images/148246/sounding-the-
seafloor-with-light; and NASA, “Oceanography,” https://swot.jpl.nasa.gov/science/oceanography/.
63 NASA, “Global Ecosystem Dynamics Investigation (GEDI),” at https://www.earthdata.nasa.gov/sensors/gedi.
64 NASA generally flies prototype instruments, which may include LiDAR, on aircraft before they are deployed into
space on satellites (NASA, remote briefing to CRS, May 24, 2023).
65 Ibid.
66 33 U.S.C. §3502. For information about the composition of IWG-OCM, see “How Are Federal Ocean and Coastal
Mapping Efforts Coordinated?”
67 For example, NOAA, NOAA Nationwide Spatial Priorities Study, NOAA Technical Memorandum NOS CS 46,
October 2021.
68 NOAA, “Spatial Priority Studies,” at https://iocm.noaa.gov/planning/priorities.html.
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Mapping the Arctic and Sub-Arctic Shoreline and Nearshore of Alaska.”69 (For more information,
see “How Have Congress and the President Directed Federal Agencies to Support Ocean and
Coastal Mapping Efforts?”)
Ocean and Coastal Waters of Alaska
According to the November 19, 2019 Presidential Memorandum on Ocean Mapping of the United
States Exclusive Economic Zone and the Shoreline and Nearshore of Alaska, Alaska “lack[s] the
comprehensive shoreline and nearshore maps available for much of the rest of the Nation” (see
Table 1).70 As directed by this presidential memorandum, in 2020, NOAA, the State of Alaska,
and the Alaska Mapping Executive Committee developed an Alaska coastal mapping strategy.71
The strategy focuses on terrestrial nearshore and coastal waters that can be mapped with LiDAR
(aircraft and satellite), roughly 2 miles landward from the coast to the seaward extinction depth of
LiDAR technology (roughly 80 m below sea level). In addition, the NOMEC Strategy calls for
mapping federal ocean water areas offshore Alaska. 72 Seascape Alaska is a regional mapping
campaign in collaboration with federal, tribal, state, and non-governmental partners to help map
U.S. EEZ off the coast of Alaska using modern multibeam sonar and LiDAR instruments.73 The
percentage of unmapped ocean and coastal waters offshore Alaska has decreased from 72% in
2020 to 66% in 2022 (Table 1).
Lakebeds of the Great Lakes
The Great Lakes are the least-mapped areas of the United States that are included in the NOMEC
Strategy (Table 1). As of January 2023, 92% of the lakebeds of the Great Lakes remained
unmapped with modern technology at a 100 m resolution.74 According to the Great Lakes
Observing System (GLOS),75 a binational network of organizations from the United States and
Canada that receives funding from NOAA, many existing bathymetric maps of the Great Lakes
were created using old, sparsely collected, or low-resolution data (e.g., water depth measurements
were collected using lead lines dropped off the edges of boats or pre-1960 using single-beam
sonar instruments).76 A priority of GLOS is the Lakebed 2030 initiative.77 Lakebed 2030 aims to
harmonize new and existing (domestic and international) governmental and nongovernmental

69 Senator Patrick Leahy, “Regarding H.R. 2617, Consolidated Appropriations Act, 2023,” remarks in the Senate,
Congressional Record, daily edition, vol. 168 (December 20, 2022), p. S7907 (hereinafter referred to as Senator Leahy,
Congressional Record).
70 Presidential Memorandum on Ocean Mapping of the U.S. EEZ, 2019.
71 The Alaska Mapping Executive Committee (AMEC) is composed of executives from the State of Alaska and 15
federal agencies and departments (AMEC, Alaska Coastal Mapping Strategy: Implementation Plan 2020-2030, June
22, p. 1).
72 Ibid., pp. 2, 4.
73 Seascape Alaska, “Introducing Seascape Alaska,” at
https://storymaps.arcgis.com/stories/094abb14281e4b2489146a3f3e030961.
74 NOAA, “Progress Report: Unmapped U.S. Waters,” March 2023, at https://iocm.noaa.gov/documents/mapping-
progress-report2023.pdf.
75 The Great Lakes Observing System (GLOS) was established in 2016. GLOS, “Lakebed 2030,” at https://glos.org/
priorities/lakebed-2030/.
76 Ibid; NOAA, “Great Lakes Bathymetry,” at https://www.ncei.noaa.gov/products/great-lakes-bathymetry; and Great
Lakes Now, “Researchers Race to Understand What Lies Beneath the Great Lakes,” July 21, 2022, at
https://www.greatlakesnow.org/2022/07/researchers-race-to-understand-what-lies-beneath-the-great-lakes/.
77 GLOS, “Lakebed 2030,” at https://glos.org/priorities/lakebed-2030/.
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bathymetric data to create new, higher-resolution maps of the Great Lakes by 2030.78 Some
stakeholders have noted that modern bathymetric data are “critical for effective management,
research, and innovation, particularly under mounting climate change threats and growing blue
economy in the Great Lakes region.”79
How Have Congress and the President Directed
Federal Agencies to Support Ocean and Coastal
Mapping Efforts?
Congress has directed multiple federal agencies to support and complete ocean and coastal
mapping over several decades. For example, Congress authorized and directed NOAA to carry
out ocean and coastal mapping activities under the Coast and Geodetic Survey Act of 1947 (P.L.
80-737), the Hydrographic Services Improvement Acts (P.L. 105-384, P.L. 107-372, and P.L. 110-
386), and the Ocean and Coastal Mapping Integration Act of 2009 (P.L. 111-11), among other
laws.80 Various entities, such as the IWG-OCM, have identified additional statutory authorities
related to ocean and coastal mapping (Table 3).81 Congress has amended some of these
authorities over time or provided additional directives in appropriations laws and accompanying
congressional reports and explanatory statements;82 those amendments and additional directives
are not listed in Table 3. For example, the Hydrographic Services Improvement Act (P.L. 105-
384) has been amended twice (P.L. 107-372 and P.L. 110-386).
Table 3. Chronology of Selected Federal Ocean and
Coastal Mapping-Related Authorities
P.L. Number or
Year
Name
Statute at Large
1870
Organic Act of 1870 (established the National Weather Service)
16 Stat. 369
1879
Organic Act of 1879 (established the United States Geological Survey)
20 Stat. 394
1916
Organic Act of 1916 (established the National Park Service)
P.L. 64-235
1938
Federal Food, Drug, and Cosmetic Act
P.L. 75-717

78 Partners of Lakebed 2030 include GLOS, USGS, NOAA, Northwestern Michigan College, and the Canadian
Hydrographic Service. Ibid.
79 GLOS, “Lakebed 2030,” at https://glos.org/priorities/lakebed-2030/. In general, the blue economy refers to the
collective economic value of the resources, uses, and activities of the ocean and coasts. For more information about the
blue economy, see CRS In Focus IF12188, What Is the Blue Economy?, by Caitlin Keating-Bitonti and Eva Lipiec.
80 Email correspondence with NOAA, Congressional Affairs Specialist, OLIA, April 18, 2023.
81 NOAA, “Integrated Ocean & Coastal Mapping, Mandates and Drivers,” at https://iocm.noaa.gov/about/
mandates.html.
82 For example, in the explanatory statement accompanying the Consolidated Appropriations Act, 2023, Congress
directed NOAA to use certain funds for “a NOAA Center of Excellence for Operational Ocean and Great Lakes
Mapping,” specifying that, “Working in unison with and leveraging existing capabilities, including the Joint
Hydrographic Center, the Center shall work across NOAA line offices, including [the National Ocean Service (NOS)],
[the Office of Oceanic and Atmospheric Administration], and the Office of Marine and Aviation Operations (OMAO),
to support and grow the Nation’s deep water, shallow water, and coastal mapping capabilities and data holdings, in
partnership with industry.” The statement also directed “NOS to continue coordinating and implementing an
interagency mapping, exploration, and characterization strategy for the U.S. Exclusive Economic Zone, as well as the
Strategy for Mapping the Arctic and Sub-Arctic Shoreline and Nearshore of Alaska consistent with prior year direction
adopted in Public Law 117–103” (Senator Leahy, Congressional Record).
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P.L. Number or
Year
Name
Statute at Large
1947
Coast and Geodetic Survey Act of 1947
P.L. 80-737
1950
National Science Foundation Act of 1950
P.L. 81-507
1953
Submerged Lands Act
P.L. 83-31
Outer Continental Shelf Lands Act
P.L. 83-212
1958
National Aeronautics and Space Act of 1958
P.L. 85-568
1966
Soil Surveys Act
P.L. 89-560
National Historic Preservation Act
P.L. 89-665
National Wildlife Refuge System Administration Act
P.L. 89-669
1969
National Environmental Policy Act
P.L. 91-190
1972
Marine Mammal Protection Act
P.L. 92-522
National Marine Sanctuaries Act
P.L. 92-532, Title III
Coastal Zone Management Act
P.L. 92-583
1973
Endangered Species Act
P.L. 93-205
1974
Deepwater Port Act of 1974
P.L. 93-627
1976
Magnuson-Stevens Fishery Conservation and Management Act
P.L. 94-265
1979
Archaeological Resources Protection Act of 1979
P.L. 96-95
1984
Arctic Research and Policy Act of 1984
P.L. 98-373
1986
Emergency Wetlands Resources Act of 1986
P.L. 99-645

Water Resources Development Act of 1986
P.L. 99-662
1987
Great Lakes Shoreline Mapping Act of 1987
P.L. 100-220, Title III,
Subtitle B
1990
Oil Pol ution Act of 1990
P.L. 101-380
Global Change Research Act of 1990
P.L. 101-606
1998
Hydrographic Services Improvement Act
P.L. 105-384
2002
Maritime Transportation Security Act of 2002
P.L. 107-295
2005
Energy Policy Act of 2005
P.L. 109-58
2007
Energy Independence and Security Act
P.L. 110-140
2009
Omnibus Public Land Management Act
P.L. 111-11
NOAA Undersea Research Program Act of 2009
P.L. 111-11, Title XII,
Subtitle A, Part II
Ocean and Coastal Mapping Integration Act of 2009
P.L. 111-11, Title XII,
Subtitle B
Integrated Coastal and Ocean Observation System Act of 2009
P.L. 111-11, Title XII,
Subtitle C
2011
National Defense Authorization Act for Fiscal Year 2012
P.L. 112-81, Title III,
Subtitle G
2015
Consolidated Appropriations Act, 2016a
P.L. 114-113
2017
Weather Research and Forecasting Innovation Act of 2017
P.L. 115-25
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P.L. Number or
Year
Name
Statute at Large
2018
Geospatial Data Act of 2018
P.L. 115-254, Title VII,
Subtitle F
2020
Digital Coast Act
P.L. 116-223
2022
National Defense Authorization Act for Fiscal Year 2023
P.L. 117-263, Division J,
Title CIII
Source: CRS; NOAA, “Integrated Ocean & Coastal Mapping, Mandates and Drivers,” at https://iocm.noaa.gov/
about/mandates.html.
Notes: The table does not include a comprehensive list of laws pertaining to ocean and coastal mapping. Laws
passed before 2017 were in part identified from a list provided on the website of the Interagency Working
Group on Ocean and Coastal Mapping.
a. The Consolidated Appropriations Act, 2016, established the Great Lakes Restoration Initiative.
In addition to congressional directives, IWG-OCM identified executive actions that further direct
federal ocean and coastal mapping. These actions include E.O. 13547, “Stewardship of the
Ocean, Our Coasts, and the Great Lakes;83 E.O. 13817, “A Federal Strategy to Ensure Secure and
Reliable Supplies of Critical Minerals”;84 E.O. 13840, “Ocean Policy to Advance the Economic,
Security, and Environmental Interests of the United States”; and the 2019 Presidential
Memorandum on Ocean Mapping of the United States Exclusive Economic Zone and the
Shoreline and Nearshore of Alaska.
Federal departments and agencies engage in ocean and coastal mapping activities under both
specific and general authorities provided by Congress that guide each agency’s mission. For
example, NOAA conducts mapping activities in state, federal, and international waters. In the
Department of the Interior, the Bureau of Ocean Energy Management (BOEM) participates in
ocean mapping activities in federal waters as part of its management of offshore energy and
mineral development; the USGS conducts ocean mapping activities in state and federal waters for
geologic, mineral, and hazard-related assessments; and the FWS maps wetlands and submerged
aquatic vegetation habitats within the coastal zone of the United States. In the Department of
Defense, USACE conducts coastal mapping for its water resource projects and responsibilities,
which primarily occur in state waters, and the U.S. Navy carries out ocean mapping activities
worldwide in support of naval missions and for some civilian purposes. Table 4 provides a
summary of selected federal department and agency ocean and coastal mapping activities.
Table 4. Selected Federal Department and Agencies Involved in U.S. Ocean and
Coastal Mapping
(listed alphabetically by department and agency)
Department
Agency
Summary of Mapping Activities
Natural Resources
NRCS maps soil resources, including those in
Conservation Service (NRCS) coastal zone areas.
Department of Agriculture
FS works with the USGS to create topographic
U.S. Forest Service (FS)
mapping products of U.S. surface waters, such as
lakes and rivers.

83 Executive Order 13547, “Stewardship of the Ocean, Our Coasts, and the Great Lakes,” 75 Federal Register 43021,
July 22, 2010.
84 Executive Order 13817, “A Federal Strategy to Ensure Secure and Reliable Supplies of Critical Minerals,” 82
Federal Register 60835, December 26, 2017.
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Department
Agency
Summary of Mapping Activities
NOAA col ects, uses, and manages ocean and
coastal mapping data to support its research,
National Oceanic and
stewardship, and public outreach missions. NOAA
Department of Commerce
Atmospheric Administration
partners with federal, state, and local agencies;
(NOAA)*
academia; nongovernmental organizations; and the
private sector to develop mapping standards and
techniques, manage data, and implement projects.
National Geospatial-
NGA provides mapping resources for coastal
Intelligence Agency (NGA)*
flood hazard analysis.
The USACE National Coastal Mapping Program
col ects elevation and imagery data around certain
U.S. coastlines about every five years in support of
its civil works activities, including for the purposes
U.S. Army Corps of Engineers of regional sediment management. USACE
(USACE)*
col aborates with the U.S. Navy, NOAA, and
USGS, along with contractor support, to conduct
Department of Defense
its coastal mapping and charting. This col aboration
is known as the Joint Airborne Lidar Bathymetry
Technological Center of Expertise.
The U.S. Navy col ects oceanographic,
hydrographic, bathymetric, geophysical, and
acoustic data to provide the warfighter knowledge
U.S. Navy*
of the battlespace. The Office of Naval Research
maps and characterizes the seafloor and water
column in support of naval missions and for some
civilian purposes.
FEMA uses LiDAR data of the U.S. coast col ected
by NOAA and USACE to conduct mapping studies
to produce Flood Insurance Rate Maps and other
Federal Emergency
products to inform coastal communities about
Management Agency (FEMA)* flood risk and other natural hazards. FEMA
Department of Homeland

evaluates and updates flood maps along populated
Security
U.S. coastlines in col aboration with other federal
agencies, states, local communities, nonprofits,
academic institutions, and the private sector.
USCG maintains more than 50,000 navigation aids,
U.S. Coast Guard (USCG)*
including buoys, lighthouses, beacons, and radio-
navigation signals, on U.S. waterways.
BOEM col ects and uses ocean mapping data as
part of its management of offshore energy and
mineral development. The data inform resource
assessments, site characterization, and
Bureau of Ocean Energy
environmental analysis, among other purposes.
Department of the Interior
Management (BOEM)*
BOEM col aborates with partners including NOAA

and USGS to map, explore, and characterize
deepwater benthic (i.e., seafloor) environments.
BOEM also col ects and manages data, such as
geological and geophysical survey data, from
offshore permittees and lessees.
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Department
Agency
Summary of Mapping Activities
NPS administers more than 80 ocean and coastal
parks and engages in benthic habitat mapping at
and around these locations. NPS’s Ocean and
National Park Service (NPS)*
Coastal Resources Program has partnered with
government agencies and universities to map
submerged habitat in parks.
FWS uses coastal and ocean mapping data to
manage resources within the U.S. marine and
coastal zone, including Marine National
Monuments and National Wildlife Refuges, among
U.S. Fish and Wildlife Service
others. FWS also uses these data to identify future
(FWS)*
waters for resource management. FWS manages
the National Wetlands Inventory, which provides
information on the extent of wetland and
submerged aquatic vegetation habitats within the
U.S. coastal zone.
The USGS col ects, uses, and manages ocean and
coastal mapping data for geologic, mineral, and
hazard-related assessments. The USGS Coastal
National Elevation Database develops integrated
U.S. Geological Survey
topobathymetric models for U.S. coastal areas, the
(USGS)*
Great Lakes, and certain Western Pacific islands
and atol s. Topobathymetric models are used to
map flood zones from hurricanes and sea-level
rise.a
The Office of Polar and Ocean Affairs facilitates
Bureau of Oceans and
diplomatic marine scientific research consent for
Department of State
International Environmental
U.S. scientists to conduct research cruises in
and Scientific Affairs
certain coastal countries while allowing foreign
scientists to conduct research in U.S. waters.
The EPA maintains an interactive mapping
application comprising over 500 maps, including
Environmental Protection
maps displaying scenarios of sea level rise
Agency (EPA)*
inundation modeled by NOAA. Most of these
maps are for the onshore continental United
States.
Independent
NASA uses ocean remote sensing technologies to
map and characterize coastal regions as part of its
ocean observing and modeling strategy. Satellite
National Aeronautics and
missions that have contributed to bathymetric
Space Administration
mapping include the Ice, Cloud and Land Elevation
(NASA)*
Satellite 2 (ICESat-2); Surface Water and Ocean
Topography (SWOT); and Joint Altimetry Satellite
Oceanography Network (JASON) series.b
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Department
Agency
Summary of Mapping Activities
NSF’s Geosciences Directorate provides federal
funding for basic research at academic institutions,
and its Division of Ocean Sciences (OCE) supports
ocean science-based projects. All ocean mapping
and characterization data collected under OCE
National Science Foundation
awards, the Academic Research Fleet, or other
(NSF)*
mechanisms are made publicly available within two
years of col ection. NSF also supports the Global
Multi-Resolution Topography Data Synthesis
initiative, a compilation of edited multibeam sonar
data col ected by scientists and institutions
worldwide.
Source: CRS; NOAA, “Integrated Ocean & Coastal Mapping, Interagency Working Group—Ocean and Coastal
Mapping,” at https://iocm.noaa.gov/about/iwg-ocm.html; and NOAA, “Integrated Ocean & Coastal Mapping,
NOAA IOCM Coordination Team,” at https://iocm.noaa.gov/about/noaa-iocm-team.html.
Notes: Agencies fol owed by an asterisk (*) are required to be a part of the Interagency Working Group on
Ocean and Coastal Mapping (IWG-OCM; 33 U.S.C. §3502(b)). Other selected agencies included in the table
were in part identified from a list provided on the IWG-OCM’s website.
a. Topobathymetric models rely on LiDAR technologies to measure three types of surfaces: land, water, and
underwater terrain.
b. For more information on selected satellites, see CRS Report R46560, Landsat 9 and the Future of the
Sustainable Land Imaging Program, by Anna E. Normand, and CRS Report R47021, Federal Involvement in
Ocean-Based Research and Development, by Caitlin Keating-Bitonti.
How Are Federal Ocean and Coastal Mapping
Efforts Coordinated?
The 2019 Presidential Memorandum on Ocean Mapping of the United States Exclusive Economic
Zone and the Shoreline and Nearshore of Alaska directed certain departments and agencies to
support federal ocean and coastal mapping efforts.85 This presidential memorandum required the
Ocean Policy Committee, working through its Ocean Science and Technology Subcommittee
(both established under E.O. 13840), to develop a mapping strategy for the U.S. EEZ.86 The
mapping scope includes both the U.S. EEZ and state waters. The strategy recommended the
creation of the National Ocean Mapping, Exploration, and Characterization (NOMEC) Council.87
The James M. Inhofe National Defense Authorization Act for Fiscal Year 2023 codified the
NOMEC Council.88
The NOMEC Council includes members from 11 federal departments and agencies: BOEM,
Department of Defense, Department of Transportation, NASA, NOAA, NSF, Office of the
Director of National Intelligence, U.S. Coast Guard, USGS, White House Office of Management

85 Presidential Memorandum on Ocean Mapping of the U.S. EEZ, 2019
86 The Ocean Policy Committee was codified by the William M. (Mac) Thornberry National Defense Authorization Act
for Fiscal Year 2021 (P.L. 116-283), Title X, Subtitle E. For more information on the structure of the Office of Science
and Technology Policy, see CRS Report R47410, The Office of Science and Technology Policy (OSTP): Overview and
Issues for Congress, by Emily G. Blevins.
87 NOMEC Strategy, 2020, p. 6.
88 P.L. 117-263, Division J, Title CIII.
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and Budget, and White House Office of Science and Technology Policy.89 The NOMEC Council
is cochaired by two senior-level representatives from NOAA and one senior-level representative
from the Department of the Interior.90 Congress passed the James M. Inhofe National Defense
Authorization Act for Fiscal Year 2023 requiring the NOMEC Council to report to the Ocean
Science and Technology Subcommittee and to oversee the work of the IWG-OCM and the
Interagency Working Group on Ocean Exploration and Characterization (Figure 5).91 Federal
agency membership may overlap or differ across the NOMEC Council, IWG-OCM, and the
Interagency Working Group on Ocean Exploration and Characterization (Table A-1).
Figure 5. Structure of the Interagency Committees, Councils, and Working Groups
with Primary Mapping, Exploration, and Characterization Responsibilities

Source: CRS; Ocean Policy Committee, Ocean Science and Technology Subcommittee, National Strategy for
Mapping, Exploring, and Characterizing the United States Exclusive Economic Zone, June 2020, p. 7.
Notes: Ocean Policy Committee was created on January 19, 2018 by Executive Order 13840 “Regarding the
Ocean Policy to Advance the Economic, Security, and Environmental Interests of the United States” and was
later codified by the James M. Inhofe National Defense Authorization Act for Fiscal Year 2021 (Title X, Subtitle
E, P.L. 116-283). NOMEC = National Ocean Mapping, Exploration, and Characterization.

89 NOAA, “NOMEC Council and Member Agencies,” at https://www.noaa.gov/nomec/nomec-council-and-member-
agencies.
90 A representative from the USGS serves as a cochair of the NOMEC Council for the Department of the Interior. Ibid
and P.L. 117-263, Division J, Title CIII, §10304(e).
91 P.L. 117-263, Division J, Title CIII.
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How Are Nonfederal Partners and Crowdsourced
Data Involved in Federal Ocean and Coastal
Mapping Efforts?
Crowdsourced bathymetric data have supported U.S. federal efforts to map U.S. ocean and
coastal waters.92 Crowdsourced bathymetric data are water-depth measurements collected using
standard navigation instruments (e.g., from vessels engaged in routine maritime operations).93
These data may supplement current bathymetric coverage and help determine whether an ocean
or coastal area needs to be remapped. They also may fill data gaps, such as data for complex
coastline areas that are difficult for traditional survey vessels to access. NOAA manages
crowdsourced bathymetric data contributed by several providers, including GLOS.94 International
seabed mapping efforts, including Seabed 2030, Lakebed 2030, and the International
Hydrographic Organization, also use crowdsourced data.95
Federal agencies participate in nonfederal partnerships to help map U.S. ocean and coastal waters.
Nonfederal partners may contribute bathymetric data and provide resources to help collect data.
For example, the USACE contracts for the aircraft to fly its LiDAR instruments.96 Offshore
energy developers also generate some ocean mapping data that are shared with the federal
government. Oil and gas companies and offshore wind developers collect geological and
geophysical survey data to locate resources or inform project siting on the outer continental
shelf.97 Under the Outer Continental Shelf Lands Act (43 U.S.C. §§1331-1356c) and
implementing regulations, BOEM is authorized to acquire such industry-collected data.98 BOEM
uses the information to support its energy resource assessments, studies of the composition and
volume of seafloor sediment deposits, identification of geological hazards and benthic habitats,
and other activities.99 However, privileged and proprietary data must be kept confidential for
specified time periods (generally ranging from 10 to 50 years), pursuant to statutory provisions.100
Nonfederal partners also may help the federal government meet its NOMEC goals (see “What
Are U.S. Goals for Ocean and Coastal Mapping?”).101 According to the NOMEC Strategy,
Academic and non-profit institutions and cooperative institutes provide the expertise for
ocean and coastal mapping, exploration, and characterization. These partnerships provide

92 For example, see NOAA, “NOAA Announces Launch of Crowdsourced Bathymetry Database,” May 31, 2018, at
https://nauticalcharts.noaa.gov/updates/noaa-announces-launch-of-crowdsourced-bathymetry-database/.
93 The Nippon Foundation-GEBCO Seabed 2030 Project, “Crowd Sourced Bathymetry,” at https://seabed2030.org/
crowd-sourced-bathymetry#.
94 NOAA, “Bathymetric Data Viewer,” at https://www.ncei.noaa.gov/maps/bathymetry/.
95 See Ibid; GLOS, “GLOS-Funded Crowdsourced Bathymetry Is Now Live on a Public Database,” October 18, 2022,
at https://glos.org/glos-funded-crowdsourced-bathymetry-is-now-live-on-a-public-database/; International
Hydrographic Organization (IHO), “IHO Crowdsourced Bathymetry Initiative” at https://www.ngdc.noaa.gov/iho/.
96 USACE, remote briefing to CRS, April 25, 2023.
97 For more information, see BOEM, “Geological and Geophysical (G&G) Surveys,” fact sheet, at
https://www.boem.gov/sites/default/files/about-boem/BOEM-Regions/Atlantic-Region/GandG-Overview.pdf.
98 43 U.S.C. §1352; 30 C.F.R. Part 551 and §§585.610-585.611.
99 See, for example, BOEM, Gulf of Mexico OCS Proposed Geological and Geophysical Activities: Final
Programmatic Environmental Impact Statement, August 2017, chapter 1, p. 4, at https://www.boem.gov/sites/default/
files/environmental-stewardship/Environmental-Assessment/NEPA/BOEM-2017-051-v1.pdf.
100 43 U.S.C. §1352(c); 30 C.F.R. §551.14.
101 NOMEC Strategy, 2020, p. 17.
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access to a wealth of ocean exploration resources, including ships, autonomous and
remotely operated vehicles, expertise, and opportunities for technology testing and
development.102
In the James M. Inhofe National Defense Authorization Act for Fiscal Year 2023, Congress
directed the NOMEC Council to “promote new and existing partnerships among Federal and
State agencies, Indian Tribes, private industry, academia, and non-governmental organizations to
conduct or support ocean mapping, exploration, and characterization activities and technological
development needs.”103 These partnerships may be employed through mechanisms such as federal
contracts, competitive grants, and cooperative research and development agreements. For
example, in 2021, NOAA entered into a memorandum of agreement with an offshore wind
development company (Ørsted Wind Power North America LLC). The company agreed to share
data collected within their leased waters subject to U.S. jurisdiction with NOAA to help fill in
ocean mapping gaps.104 In another example, NOAA announced the creation of the Brennan
Matching Fund (BMF) in 2021 to encourage nonfederal entities to partner with NOAA to acquire
more ocean and coastal survey data.105 In 2022, Congress codified the BMF through the James M.
Inhofe National Defense Authorization Act for Fiscal Year 2023. In FY2023, NOAA provided
funding for two BMF projects.
1. NOAA’s partnership with the Connecticut Department of Energy and
Environmental Protection aims to use multibeam and backscatter approaches to
identify potential constraints for the installation of offshore wind electric
transmission cables.
2. NOAA’s partnership with the Cordova, AK, Electric Cooperative aims to use
LiDAR to support the laying of an undersea power cable to a regional Federal
Aviation Administration flight station.106
Congress may wish to evaluate the work and progress of congressionally directed or funded
federal and nonfederal partnerships aimed at collecting and analyzing new bathymetric data.
Congressional oversight may determine if the efforts of these partnerships are contributing to the
goals of the NOMEC Strategy. In addition, Congress may consider whether to continue providing
funding to public-private ocean and coastal mapping partnerships.

102 Ibid, pp. 17-18.
103 P.L. 117-263, Division J, Title CIII, §10304(i)(2)(G).
104 Ørsted bathymetric data are made available on NOAA’s Bathymetric Data Viewer
(https://www.ncei.noaa.gov/maps/bathymetry/). NOAA, “NOAA Signs Data-Share Agreement with Offshore Wind
energy Company,” at https://www.noaa.gov/media-release/noaa-signs-data-share-agreement-with-offshore-wind-
energy-company.
105 For example, NOAA, “Notice of Matching Fund Opportunity for Ocean and Coastal Mapping and Request for
Partnership Proposals,” 87 Federal Register 35509, June 10, 2022.
106 Email correspondence with NOAA, Congressional Affairs Specialist, OLIA, April 14, 2023.
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Appendix.
Over 20 federal agencies, departments, and offices participate in aspects of ocean and coastal
mapping, exploration, or characterization. Federal agency membership may overlap or differ
across the National Ocean Mapping, Exploration, and Characterization (NOMEC) Council,
Interagency Working Group on Ocean and Coastal Mapping (IWG-OCM), and Interagency
Working Group on Ocean Exploration and Characterization (IWG-OEC). (See Table A-1.)
Table A-1. Selected Federal Departments, Agencies, and Offices Involved in U.S.
Ocean and Coastal Mapping

Coordination Body Membership
NOMEC
Federal Department, Agency, or Office
Councila
IWG-OCMb
IWG-OECc
Bureau of Ocean Energy Management
X
X
X
Department of Defense
X
—
—
Department of Energy
—
—
X
Department of the Interior, Office of the Assistant Secretary
—
X
—
for Fish, Wildlife, and Parks
Department of Transportation
X
—
—
Environmental Protection Agency
—
X
—
Federal Emergency Management Agency
—
X
—
National Aeronautics and Space Administration
X
X
X
National Geospatial-Intelligence Agency
—
X
—
Office of the Secretary of Defense
—
—
—
National Oceanic and Atmospheric Administration
X
X
X
National Park Service
—
X
—
National Science Foundation
X
X
X
U.S. Coast Guard
X
X
—
U.S. Fish and Wildlife Service
—
X
—
U.S. Food and Drug Administration
—
—
X
U.S. Geological Survey
X
X
X
U.S. Army Corps of Engineers
—
X
—
U.S. Navy
—
X
X
U.S. Park Service
—
—
—
White House Office of Management and Budget
X
—
X
White House Office of the Director of National Intelligence
X
—
X
White House Office of Science and Technology Policy
X
—
X
Source: Congressional Research Service.
Notes: IWG-OCM = Interagency Working Group on Ocean and Coastal Mapping; IWG-OEC = Interagency
Working Group on Ocean Exploration and Characterization (IWG-OEC); NOMEC = National Ocean Mapping,
Exploration, and Characterization.
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a. Membership identified from National Oceanic and Atmospheric Administration, “NOMEC Council and
Member Agencies,” at https://www.noaa.gov/nomec/nomec-council-and-member-agencies.
b. Membership identified in 33 U.S.C. §3502(b).
c. Membership identified from the IWG-OEC, Strategic Priorities for Ocean Exploration and Characterization of the
United States Exclusive Economic Zone, October 2022, p. 4.

Author Information

Caitlin Keating-Bitonti, Coordinator
Christopher R. Field
Analyst in Natural Resources Policy
Analyst in Natural Resources Policy

Nicole T. Carter
Eva Lipiec
Specialist in Natural Resources Policy
Analyst in Natural Resources Policy

Laura B. Comay
Linda R. Rowan
Specialist in Natural Resources Policy
Analyst in Natural Resources and Earth Sciences

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan
shared staff to congressional committees and Members of Congress. It operates solely at the behest of and
under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other
than public understanding of information that has been provided by CRS to Members of Congress in
connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not
subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in
its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or
material from a third party, you may need to obtain the permission of the copyright holder if you wish to
copy or otherwise use copyrighted material.

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