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Title 33 — Navigation and Navigable WatersRelease 119-73not60

§151 High Seas and Inland Waters Demarcation Lines

Title 33 › Chapter 3— NAVIGATION RULES FOR HARBORS, RIVERS, AND INLAND WATERS GENERALLY › Subchapter I— PRELIMINARY › § 151

Last updated Apr 5, 2026|Official source

Summary

The Secretary of the department that runs the Coast Guard must draw clear lines that separate the high seas from harbors, rivers, and other inland waters. Those lines tell when special navigation rules apply instead of the international collision rules. The Secretary must also draw lines to decide when laws that refer to this rule apply. Those lines cannot be more than 12 nautical miles out from the baseline used to measure the territorial sea, and they can be in different places for different laws. United States — includes the several States, the District of Columbia, Puerto Rico, Guam, American Samoa, the U.S. Virgin Islands, the Commonwealth of the Northern Mariana Islands, the Trust Territory of the Pacific Islands, and any other U.S. commonwealth, territory, or possession.

Full Legal Text

Title 33, §151

Navigation and Navigable Waters — Source: USLM XML via OLRC

(a)The Secretary of the department in which the Coast Guard is operating shall establish appropriate identifiable demarcation lines dividing the high seas from harbors, rivers, and other inland waters of the United States, for the purpose of determining the applicability of special navigational rules in lieu of the International Regulations for Preventing Collisions at Sea.
(b)The Secretary shall also establish appropriate identifiable lines dividing inland waters of the United States from the high seas for the purpose of determining the applicability of each statute that refers to this section or this section, as amended. These lines may not be located more than twelve nautical miles seaward of the base line from which the territorial sea is measured. These lines may differ in position for the purposes of different statutes.
(c)For the purposes of this section, the term “United States” includes the several States of the United States, the District of Columbia, the Commonwealth of Puerto Rico, Guam, American Samoa, the United States Virgin Islands, the Commonwealth of the Northern Mariana Islands, the Trust Territory of the Pacific Islands, and any other Commonwealth, territory, or possession of the United States.

Legislative History

Notes & Related Subsidiaries

Editorial Notes

References in Text

The International

Regulations

for Preventing Collisions at Sea, referred to in subsec. (a), came into effect pursuant to the Convention on the International

Regulations

for Preventing Collisions at Sea, 1972. See International

Regulations

for Preventing Collisions at Sea, 1972 note under section 1602 of this title. Codification Section was not enacted as part of act June 7, 1897, ch. 4, 30 Stat. 96, which comprises a major part of this chapter.

Amendments

1980—Subsec. (a). Pub. L. 96–324 designated existing provisions as subsec. (a), substituted provision authorizing the Secretary of the Department in which the Coast Guard is operating to establish demarcation lines for provision authorizing the Secretary of the Treasury to establish demarcation lines, and inserted provision specifying the purpose of establishing demarcation lines as determining the applicability of special navigational rules in lieu of the International

Regulations

for Preventing Collisions at Sea. Subsec. (b). Pub. L. 96–324 added subsec. (b). Subsec. (c). Pub. L. 96–591 and Pub. L. 96–376 made identical

Amendments

by striking out reference to the Canal Zone. Pub. L. 96–324 added subsec. (c).

Statutory Notes and Related Subsidiaries

Transfer of Functions

For transfer of authorities, functions, personnel, and assets of the Coast Guard, including the authorities and functions of the Secretary of Transportation relating thereto, to the Department of Homeland Security, and for treatment of related references, see section 468(b), 551(d), 552(d), and 557 of Title 6, Domestic Security, and the Department of Homeland Security Reorganization Plan of November 25, 2002, as modified, set out as a note under section 542 of Title 6.

Executive Documents

Termination of Trust Territory of the Pacific Islands For termination of Trust Territory of the Pacific Islands, see note set out preceding section 1681 of Title 48, Territories and Insular Possessions. Territorial Sea of United States For extension of territorial sea of United States, see Proc. No. 5928, set out as a note under section 1331 of Title 43, Public Lands.

Reference

Citations & Metadata

Citation

33 U.S.C. § 151

Title 33 — Navigation and Navigable Waters

Last Updated

Apr 5, 2026

Release point: 119-73not60