What does COLREGs Rule 11 say?

In full: “Rules 11 through 18 apply to vessels in sight of one another.” It is the shortest substantive rule in the book, and it defines the scope of Part B Section II — the steering and sailing rules that assign give-way and stand-on roles.

Which rules does Rule 11 apply to?

Rules 12 through 18: sailing vessels (12), overtaking (13), head-on (14), crossing (15), action by the give-way vessel (16), action by the stand-on vessel (17), and responsibilities between vessels (18). Rule 11 itself is the scoping sentence for all of them.

Does being in sight include radar contact?

No. Rule 3 makes being in sight of one another a matter of visual observation. A target tracked on radar in fog is not in sight, so Rules 12 through 18 do not apply to it — Rule 19 does, and Rule 19(d) is written specifically for action taken on radar information alone.

Why does Rule 11 matter if it is only one sentence?

Because it decides which rulebook chapter you are in. In clear visibility a crossing situation has a give-way vessel and a stand-on vessel with defined duties. The moment visibility closes and the vessels are no longer visually observed, those roles disappear and both vessels are independently obliged to avoid collision under Rule 19. Answers that keep applying the crossing rule in fog fail on Rule 11.

COLREGs Rule 11 — In Sight of One Another (Rules 11–18)

Rule text#

Source

The international COLREGs text is published by the IMO and is not available to reproduce here. Shown below is the U.S. counterpart, 33 CFR §83.11, which tracks the international wording closely. Where the two diverge, see where inland differs.

Rules 11 through 18 (§§ 83.11 through 83.18) apply to vessels in sight of one another.

Why it shows up on the exam#

Rule 11 is short enough to skip and load-bearing enough to sink an answer. Rule 3(k) defines being in sight as being *visually* observed, so a radar contact in fog is not in sight — which is exactly why Rule 19 has no stand-on vessel. Questions that put two vessels in restricted visibility and then offer a give-way/stand-on answer are testing Rule 11 through the back door.

Exam checkpoints#

The whole rule
Rules 11–18, in sight only
“Rules 11 through 18 apply to vessels in sight of one another.” That is the complete text. It scopes every steering and sailing rule that assigns a give-way or stand-on role.
What “in sight” means
Visually observed (Rule 3)
Rule 3 defines vessels as in sight of one another only when one can be observed visually from the other. Detecting a vessel on radar, AIS or by sound signal does not satisfy it.
What it switches off
Give-way and stand-on
Because Rules 15 through 17 sit inside Section II, the crossing rule and the stand-on vessel's duties simply do not apply between vessels not in sight of one another. Rule 19 governs instead, and it gives neither vessel the right to hold course and speed.

Where Inland differs#

Inland Rule 11 (33 CFR §83.11) is identical to COLREGs Rule 11 — one of the rules where the two rulebooks do not diverge at all.

Rule 11 — common exam questions#

What does COLREGs Rule 11 say?: In full: “Rules 11 through 18 apply to vessels in sight of one another.” It is the shortest substantive rule in the book, and it defines the scope of Part B Section II — the steering and sailing rules that assign give-way and stand-on roles.
Which rules does Rule 11 apply to?: Rules 12 through 18: sailing vessels (12), overtaking (13), head-on (14), crossing (15), action by the give-way vessel (16), action by the stand-on vessel (17), and responsibilities between vessels (18). Rule 11 itself is the scoping sentence for all of them.
Does being in sight include radar contact?: No. Rule 3 makes being in sight of one another a matter of visual observation. A target tracked on radar in fog is not in sight, so Rules 12 through 18 do not apply to it — Rule 19 does, and Rule 19(d) is written specifically for action taken on radar information alone.
Why does Rule 11 matter if it is only one sentence?: Because it decides which rulebook chapter you are in. In clear visibility a crossing situation has a give-way vessel and a stand-on vessel with defined duties. The moment visibility closes and the vessels are no longer visually observed, those roles disappear and both vessels are independently obliged to avoid collision under Rule 19. Answers that keep applying the crossing rule in fog fail on Rule 11.

Authoritative source#

Source links checked against the current public rule corpus on 2026-07-26.

33 CFR §83.11 — the section this text comes from, with its neighbours.
International COLREGs Rule 11 verbatim text is published by the IMO and is authoritative for international waters.

Practice this rule#

One real exam question on this rule, cited to source. No sign-up.

Under 46 CFR §11.302, a seafarer who cannot demonstrate 1 year of sea service within the last 5 years to maintain basic training (BT) competence is required to do which of the following?

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