Rule 5 (lookout)

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 prevailing circumstances and conditions, so as to make a full appraisal of the situation and the risk of collision. The phrase covers the unaided senses plus radar, ARPA, AIS, VHF, and any other equipment carried. A bridge reduced to one person in restricted visibility, or a lookout doubling as helmsman in darkness, has repeatedly been found in breach in collision casualties.