Module 5 - COLREGs
Rule 5 — Look-out
What you will learn
Organise and hand over a continuous lookout that combines people, sight, hearing, radar and other appropriate means into one shared traffic picture.
A proper lookout is an active watch system. Equipment extends the picture, but only competent attention, clear roles and repeated scans keep it complete.
Rule 5 requires every vessel at all times to maintain a proper lookout by sight and hearing as well as by all available means appropriate to the circumstances. The purpose is a full appraisal of the situation and risk of collision, so a periodic glance, an alarm setting or a list of targets is not enough.
Scan the full horizon, deliberately clear blind sectors around sails and structures, listen from a useful position and rebuild the picture after course, speed, visibility, traffic or watch changes. When workload prevents one person doing this continuously, call another competent lookout before the picture degrades.
Radar should be set and used properly when fitted and operational. AIS may add identity and reported movement, but transmissions can be absent or wrong and AIS course and speed are normally over the ground. Autopilot holds a command; it neither keeps a lookout nor understands collision risk. A handover should transfer relative bearings, ranges, trends, blind sectors, equipment limits and call-the-skipper triggers.
Hand over a busy night watch
The yacht is under autopilot near an approach channel. A large genoa masks the leeward bow, rain clutter is increasing and two AIS targets are named.
1. Restore the blind sector
Move the scan position or post another lookout so the obscured bow is checked deliberately.
2. Describe the evidence
Give relative bearings, ranges, trends and radar limits; use AIS names only as supplementary labels.
3. Transfer responsibility
Confirm the incoming watch has found the contacts and understands the call limits before leaving.
Sense check: If the handover misses an unlit dinghy, buoy or sound signal because it does not transmit AIS, the lookout plan is incomplete.
Common mistake or limitation
- AIS cannot be the sole lookout: not every target transmits and transmitted data can be missing or wrong.
- A handover made from vessel names loses the relative position, trend and uncertainty needed for collision assessment.
Recap
- Rule 5 requires a continuous full appraisal by sight, hearing and all appropriate available means.
- Blind sectors and workload must be actively managed.
- A safe handover transfers the observed traffic picture, equipment limits and escalation triggers.
Optional quick check
Section 3 of 14
Which handover best preserves a proper lookout?
Sources and factual review
Reviewed 2 September 2026 - Compass Revision editorial review.
Continue studying COLREGs
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