Rules of the Road
Inland Navigation Rules — all 37 US rules
33 CFR Part 83 — 37 rules across five parts. They mirror the international COLREGs almost verbatim with a handful of structural deviations: Inland Rule 10 covers Vessel Traffic Services rather than Traffic Separation Schemes, there is no Inland Rule 28 (constrained-by-draft is COLREGs-only), and Western-Rivers and Great-Lakes traffic gets descending-current right of way under several rules.
33 CFR Part 8337 rules · Parts A–ELast verified
Looking for the international set? See the COLREGs directory.
Where Inland diverges from COLREGs#
Five rules carry exam-relevant differences. Read each pair together — see the full side-by-side comparison for the rest.
- Rule 9COLREGs version omits the descending-current right of way Inland adds
- Rule 10COLREGs Rule 10 covers IMO Traffic Separation Schemes, not VTS
- Rule 24Standard tow-light progression — no Inland composite-unit/Western-Rivers exceptions
- Rule 28COLREGs-only — constrained-by-draft (three vertical red lights). Inland skips 27 → 29.
- Rule 34COLREGs sound signals describe action (“I am altering course”), not intent
Start with the collision-avoidance sequence#
Read these five rules as a set before working through the full directory.
- Rule 5Look-out
- Rule 6Safe Speed
- Rule 7Risk of Collision
- Rule 8Action to Avoid Collision
- Rule 9Narrow Channels
Ready to test yourself? Work the free Rules of the Road practice questions — no sign-in, citation-backed against 33 CFR Part 83 — or browse practice questions for every exam module.
All 37 Inland Rules by Part#
Part A — General
Rules 1-3: application (and the 33 CFR Part 80 demarcation lines that fix where Inland applies), responsibility, definitions.
Part B-I — Conduct in Any Visibility
Rules 4-10: lookout, safe speed, risk of collision, action to avoid, narrow channels, and Vessel Traffic Services — Inland Rule 10 is VTS, not Traffic Separation Schemes.
Part B-II — In Sight of One Another
Rules 11-18: sailing vessels, overtaking, head-on, crossing, give-way / stand-on action, responsibilities between vessels.
Part B-III — Restricted Visibility
Rule 19: conduct in fog, snow, heavy rain.
Part C — Lights and Shapes
Rules 20-31, skipping Rule 28 (constrained-by-draft is COLREGs-only): visibility, definitions, and per-vessel-type light and shape displays.
- 20Application (Lights and Shapes)33 CFR §83.20
- 21Definitions (Lights)33 CFR §83.21
- 22Visibility of Lights33 CFR §83.22
- 23Power-driven Vessel Underway33 CFR §83.23
- 24Towing and Pushing33 CFR §83.24
- 25Sailing Vessels Underway and Vessels Under Oars33 CFR §83.25
- 26Fishing Vessels33 CFR §83.26
- 27Vessels Not Under Command or Restricted in Their Ability to Maneuver33 CFR §83.27
- 29Pilot Vessels33 CFR §83.29
- 30Anchored Vessels and Vessels Aground33 CFR §83.30
- 31Seaplanes33 CFR §83.31
Part D — Sound and Light Signals
Rules 32-37: equipment, maneuvering signals of intent, restricted-visibility fog signals, distress signals.
Frequently asked#
How many Inland Navigation Rules are there?
37 numbered rules in 33 CFR Part 83, grouped into five parts (A through E). Inland carries one fewer than COLREGs' 38 navigation Rules (Parts A–E) because there is no Inland Rule 28 — 'constrained by draft' is COLREGs-only, so the Inland numbering jumps straight from Rule 27 to Rule 29.
What CFR are the Inland Navigation Rules in?
33 CFR Part 83. The technical annexes — light positioning, sound-signal appliances, distress signals, and pilot rules — are in 33 CFR Parts 84-88, and the COLREGS demarcation lines that fix where the Inland Rules take over from the international rules are in 33 CFR Part 80.
Where do the Inland Navigation Rules apply?
Shoreward of the COLREGS demarcation lines fixed by 33 CFR Part 80 — most US harbors, bays, rivers, the Great Lakes, and Western Rivers. Outside those lines, on the high seas and connected coastal waters, the international COLREGs control. A single coastal transit can cross between the two rule sets.
How is Inland Rule 34 different from COLREGs Rule 34?
Under the Inland Rules, maneuvering whistle signals are signals of intent that must be answered and agreed before either vessel acts: one short blast means 'I intend to leave you on my port side', two short blasts means 'on my starboard side'. Under COLREGs the identical signals describe action already being taken ('I am altering my course to starboard'). This intent-versus-action distinction is one of the most-tested Rules of the Road exam points.
Are the Inland Rules and COLREGs the same?
They mirror each other almost word-for-word, with five exam-relevant divergences — Rules 9, 10, 24, 28, and 34 — plus Western-Rivers and Great-Lakes provisions. The /vs/inland-vs-international-rules page lists each line-by-line difference.
Primary sources#
Checked against the current public rule corpus on .
- 33 CFR Part 83 — Inland Navigation Rules (eCFR current issue) (retrieved 24 May 2026)
- 33 CFR Part 80 — COLREGS Demarcation Lines (eCFR current issue) (retrieved 24 May 2026)
- 33 CFR Subchapter E — Inland Navigation Rules Annexes, Parts 84-88 (eCFR current issue) (retrieved 24 May 2026)
- USCG Navigation Center — Navigation Rules, International—Inland (Amalgamated) (retrieved 24 May 2026)
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