Study guide
Rules of the road: who gives way
Two vessels, one risk of collision. The Navigation Rules decide who acts and how. These are the ones to know first.
Every vessel, all the time
- Look-out. By sight and hearing, and by all available means (Rule 5).
- Safe speed. Fast enough to act and slow enough to stop in the distance the conditions call for (Rule 6).
- Risk of collision. If there is any doubt, risk is deemed to exist (Rule 7).
- Action. Positive, in ample time, and large enough for the other vessel to see (Rule 8).
The three situations
Overtaking (Rule 13)
Any vessel overtaking another keeps out of the way. You’re overtaking when you come up from more than 22.5 degrees abaft the other vessel’s beam. If you’re in doubt, assume you are. This beats every other steering rule from 4 to 18.
Head-on (Rule 14)
Two power-driven vessels on reciprocal or nearly reciprocal courses each alter to starboard and pass port to port. If in doubt, assume it’s head-on.
Crossing (Rule 15)
The power-driven vessel with the other on her starboard side keeps out of the way and, if she can, avoids crossing ahead.
Give-way and stand-on
Give-way vessel (Rule 16). Take early and substantial action to keep well clear.
Stand-on vessel (Rule 17). Keep your course and speed. You may act by your maneuver alone once it’s clear the other vessel isn’t acting, and you must act when collision can’t be avoided by the give-way vessel alone.
Who keeps clear of whom (Rule 18)
Unless Rules 9, 10 or 13 say otherwise, read this from top to bottom. Each vessel keeps clear of those listed for it.
| This vessel, underway | Keeps out of the way of |
|---|---|
| Power-driven | Not under command, restricted in ability to maneuver, engaged in fishing, sailing |
| Sailing | Not under command, restricted in ability to maneuver, engaged in fishing |
| Engaged in fishing | So far as possible: not under command, restricted in ability to maneuver |
Where Inland differs
| Topic | International | Inland |
|---|---|---|
| One short blast | I am altering my course to starboard. A statement of action | I intend to leave you on my port side. A proposal the other vessel answers |
| Overtaking signals | In a narrow channel: two prolonged and one or two short. Agreement is prolonged, short, prolonged, short | In sight, any waters: one short for your starboard side, two for your port side. Agreement is a similar signal |
| Leaving a dock | No equivalent | One prolonged blast (Rule 34(g)) |
| Radio agreement | No equivalent | Whistle signals aren’t obliged once agreed (Rule 34(h)) |
| Rivers and Great Lakes | No equivalent | A downbound power vessel with a following current has the right of way and proposes the passage (Rules 9, 14(d)). A power vessel crossing a river keeps clear of one going up or down it (Rule 15(b)) |
Hear each of these on the sound signals page, and test yourself with the free Rules of the Road practice test.
Common questions
Who has the right of way when two power boats cross?
The vessel with the other on her starboard side keeps out of the way, and avoids crossing ahead if she can (Rule 15). The other vessel keeps her course and speed (Rule 17).
Does a sailboat always have the right of way?
No. A power-driven vessel keeps clear of a sailing vessel (Rule 18), but a sailing vessel overtaking a power-driven vessel must keep clear, and a sailing vessel gives way to a vessel not under command, restricted in her ability to maneuver, or engaged in fishing.
What do you do when you meet another vessel head-on?
Two power-driven vessels each alter course to starboard, so each passes on the port side of the other (Rule 14).
How do I practice for a rules of the road test?
Learn the steering rules first, then drill lights and sound signals, and mix International and Inland questions so you notice where the wording changes.
Make it automatic
Helm has Rules of the Road questions in every topic, each one showing the rule behind its answer.
Start freeKeep studying
- Free OUPV practice testReal sample questions, each with its rule. No sign-up.
- Sound signalsEvery horn, bell and fog signal, with audio and citations.
- Lights and shapesWhat each vessel shows at night and by day.
- What the exam coversThe modules, and what to confirm in your letter.
- Six-pack licenseWho needs one and what the regulations ask for.
- BuoysRed right returning, and what each mark means.
Sources
- USCG NAVCEN, Amalgamated Navigation Rules
- 33 CFR 83.13, overtaking
- 33 CFR 83.14, head-on
- 33 CFR 83.15, crossing
- 33 CFR 83.18, responsibilities between vessels
- 33 CFR 83.34, maneuvering and warning signals
Helm is an independent study aid, not affiliated with or endorsed by the U.S. Coast Guard or the National Maritime Center. This page is for study, not navigation guidance or legal advice. Check the current rules before you rely on anything here.