International or Inland Rules: which apply where

Navigation Rules, lights & bridges · Power & sail

Two rule sets govern US waters: the International Rules (COLREGS) seaward of the demarcation lines in 33 CFR 80, and the Inland Rules (33 CFR 83) shoreward of them and on the Great Lakes. Most rules are identical; the differences show up mainly in whistle signals and a few river rules.

Where each set applies

• The International Rules (72 COLREGS) apply to US vessels on the high seas and connected waters navigable by seagoing vessels, and to all vessels in US waters outside the demarcation lines (33 U.S.C. 1603; 33 CFR 80.01).
• The Inland Rules apply to every vessel on US inland waters: waters shoreward of the demarcation lines plus the US side of the Great Lakes. US boats also follow them on Canada's Great Lakes waters where they don't conflict with Canadian law (33 CFR 83.01(a), 83.03(q)).
• 33 CFR Part 80 describes each demarcation line coast by coast, using landmarks, lights and coordinates. Inside the line you follow the Inland Rules; outside it, the COLREGS (33 CFR 80.01(b)).
• Some regions have no inland zone for most bays and harbors. The COLREGS apply on all of Puget Sound (including Lake Union, Lake Washington and Hood Canal), the Strait of Juan de Fuca, and all Alaskan sounds, bays and harbors (33 CFR 80.1385, 80.1395, 80.1705).
• The COLREGS also apply on most Hawaiian bays and harbors, except the specific harbors listed in Part 80 (33 CFR 80.1410). Read the Part 80 section for your coast rather than assuming a harbor is Inland Rules water.

Carrying a copy of the Rules

• The operator of every self-propelled vessel 12 meters (39.4 ft) or longer must carry a copy of the Inland Navigation Rules aboard and keep it handy for reference (33 CFR 83.01(g)).
• The Coast Guard says its online amalgamated Rules, NOAA's printed Navigation Rules handbook, or the Rules printed in each US Coast Pilot volume can be used to meet that requirement. It points to NVIC 01-16, Change 2, for its policy on electronic copies.

Great Lakes, Western Rivers and listed rivers

• On these waters, a power-driven vessel going downbound with a following current has the right-of-way over an upbound vessel in narrow channels and head-on meetings. It proposes how to pass and gives the whistle signals first (Inland Rules 9(a)(ii), 14(d)).
• On the same waters, a power-driven vessel crossing a river keeps out of the way of power-driven vessels going up or down the river (Inland Rule 15(b)).
• The listed waters are the Tennessee-Tombigbee Waterway; the Tombigbee, Black Warrior, Alabama, Coosa, Flint and Chattahoochee Rivers; the Mobile River above Cochrane Bridge; and the Apalachicola above the Jackson River (33 CFR 89.25).
• 'Western Rivers' means the Mississippi and its tributaries, South and Southwest Passes, the Port Allen-Morgan City Alternate Route, and parts of the Atchafalaya, Old and Red Rivers (33 CFR 83.03(n)).

State rules

• States and local governments can enforce their own navigation rules as well. In 2023 the Coast Guard deleted a 2014 sentence in 33 CFR 83.01(a) that claimed federal pre-emption of the whole field. Only state rules that conflict with federal law are pre-empted (Federal Register, June 12, 2023).
• Some state rules and handbooks still repeat older wording, such as a bell from 12 meters. Check your state's boating rules alongside the federal Rules.

The rules: Inland Rule 1 · COLREGS Rule 1 · 33 CFR 83.01 · 33 CFR 83.03 · 33 U.S.C. 1603 · 33 U.S.C. 1604 · 33 CFR 80.01 · 33 CFR 80.1385 · 33 CFR 80.1395 · 33 CFR 80.1410 · 33 CFR 80.1705 · 33 CFR 89.25 · Inland Rule 9 · Inland Rule 14 · Inland Rule 15

A plain-language summary of federal rules for recreational boats, checked against the rules’ own text and a second source, and written in our own words. It isn’t legal advice. States add rules of their own, and rules change — the links above go to the current official text.