The rule in plain words
- Who and when?Your vessel shall maintain a proper look-out at all times. The duty applies to every vessel.
- How?Look and listen: the look-out must be by sight and hearing. Both are part of a proper look-out.
- What else do you use?Also use all available means appropriate in the prevailing circumstances and conditions, such as radar or AIS.
- What is it for?With this look-out, you make a full appraisal of the situation and of the risk of collision.
Before you read on: what would you do?
Who must comply with Rule 5, and when?
Frequent mistakes
Wrong: "A look-out matters only when traffic is busy."
Right: Rule 5 requires you to maintain it at all times.
Wrong: "A small leisure craft is outside Rule 5."
Right: The rule says every vessel; it creates no such exemption.
Wrong: "Radar or AIS replace looking and listening."
Right: Radar and AIS add means; they do not replace look-out by sight and hearing.
Exam keys & interpretation
- If an option exempts an anchored vessel or small leisure craft, reject it: the rule says "every vessel".
- "Radar/AIS" does not replace "sight and hearing": check whether the option adds means or removes the look-out.
- If asked for the purpose, look for a full appraisal of situation and collision risk, not merely detecting another vessel.
How to read it
"Appropriate" depends on the prevailing circumstances and conditions: use available means that help you make a full appraisal of the situation.
"As well as" adds means to sight and hearing; it does not turn equipment into a substitute for the look-out.
Key points
- Universal duty · continuous look-out.
- Sight + hearing → proper look-out.
- Available means = appropriate to the moment.
- Purpose → full situation appraisal + collision risk.
Test your knowledge
3 questions to check it. Pick an answer to see why.
Which combination expresses the required look-out?