Rule 5: Look-out (COLREGS)
Last reviewed October 21, 2026
The short answer
Rule 5 says every vessel must at all times keep a proper look-out by sight and hearing, and by all available means appropriate to the circumstances, so she can make a full appraisal of the situation and of the risk of collision. Radar and other tools count as available means.
The rule text
Every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision.
International Rules, U.S. Coast Guard Navigation Rules and Regulations Handbook (NAVCEN, 2024 corrected edition), Rule 5
What it means on the water
- Every vessel, at all times, including at anchor watch and in clear weather.
- Sight and hearing plus all available means, such as radar.
- The goal is a full appraisal of the situation and of the risk of collision.
International vs Inland
Same in both International and Inland.
Common exam traps
- Thinking radar replaces the visual look-out.
- Thinking small boats are exempt.
Try 3 questions on Rule 5
Rule 5 requires a look-out by:
- Sight only
- Sight, hearing, and all available means
- Radar only
- Radio only
Show answer
B. Sight, hearing, and all available means Rule 5.
When must a look-out be kept?
- Only at night
- Only in fog
- At all times
- Only underway in traffic
Show answer
C. At all times Rule 5.
Is Rule 5 the same Inland?
- Yes
- No
Show answer
A. Yes Same text.
Frequently asked questions
Does radar satisfy Rule 5?
Radar is one available means, but Rule 5 also requires sight and hearing.
Do small boats need a look-out?
Yes. Rule 5 applies to every vessel.
Same Inland?
Yes.