COLREGS Rule 5 — Look-out

Rule Text

What it means on the water

• →Look-out must be maintained at ALL TIMES — day, night, clear weather, restricted visibility.
• →Both sight AND hearing are required — not just visual scanning.
• →All available means includes radar, AIS, VHF, and any other sensor fitted.
• →The purpose is a full appraisal of the situation AND of the risk of collision.
• →A dedicated look-out (separate from the helmsman) is required on larger vessels in most circumstances.

Common exam mistakes

• ✗Thinking look-out only applies in restricted visibility — Rule 5 says 'at all times.'
• ✗Forgetting that hearing (listening for sound signals and fog signals) is an explicit requirement.
• ✗Missing that radar is included as part of a proper look-out when fitted.

USCG exam questions — Rule 5

These questions are drawn from the same pool used in real USCG licensing exams. Correct answers and explanations are shown.

1. 1. Under 72 COLREGS Rule 5, a proper lookout shall be maintained:

   • A.By sight and hearing only when visibility is reduced below 1 nautical mile
   • B.By sight and hearing at all times, using all available means appropriate to the prevailing circumstances✓
   • C.By radar when operating in restricted visibility and by visual means at all other times
   • D.By the officer of the watch, supplemented by radar as required by flag state regulations

   Why: Rule 5 requires a proper lookout by sight AND hearing at ALL times, using ALL available means appropriate to the prevailing circumstances and conditions. This is an absolute, continuous duty — not conditional on visibility conditions — and 'all available means' includes radar, AIS, and other technology.

2. 2. Which factor is NOT listed in Rule 6 as relevant to determining a safe speed?

   • A.The state of visibility
   • B.The maneuverability of the vessel with special reference to stopping distance
   • C.The number of persons on board✓
   • D.The background light at night from shore lights or from backscatter of own lights

   Why: Rule 6 lists specific factors for safe speed: visibility, traffic density, maneuverability (stopping distance, turning ability), background light, sea state, draft versus available depth, radar range/resolution, and whether radar is in use. The number of persons on board is not among the enumerated factors.

3. 3. A vessel equipped with radar determines by radar plotting that risk of collision may exist. Under Rule 6, this is relevant because:

   • A.A radar-equipped vessel must proceed at reduced speed whenever a contact is detected within 10 miles
   • B.The state of weather and sea conditions alters the interpretation of radar returns
   • C.Radar characteristics, efficiency, and limitations are a factor in determining safe speed✓
   • D.A radar-equipped vessel is always deemed to have complied with the lookout requirement

   Why: Rule 6(b) specifically lists factors relevant to safe speed for radar-equipped vessels, including the characteristics, efficiency, and limitations of the radar equipment. A vessel must account for what radar can and cannot detect when choosing a speed that allows stopping in time.

4. 4. Rule 5 requires every vessel to maintain a proper lookout at all times. Which of the following BEST describes the purpose of a proper lookout?

   • A.To make a full appraisal of the situation and of the risk of collision✓
   • B.To watch for vessels displaying distress signals only
   • C.To monitor radar exclusively when in restricted visibility
   • D.To maintain a visual watch during daylight hours only

   Why: Rule 5 requires every vessel to maintain a proper lookout by sight and hearing, as well as by all available means appropriate in the prevailing circumstances, so as to make a full appraisal of the situation and of the risk of collision. The lookout duty is continuous and all-encompassing.

5. 5. Under COLREGS Rule 5, a proper lookout shall be maintained by:

   • A.Sight and hearing as well as all available means appropriate to the circumstances✓
   • B.Visual watch only during restricted visibility
   • C.Radar watch only in open ocean passages
   • D.Two designated officers posted at the bow and stern

   Why: Rule 5 specifies that every vessel shall at all times maintain a proper lookout by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions. This comprehensive requirement includes radar, AIS, and other detection systems.

6. 6. The officer of the watch on a vessel at sea decides that the helmsman can also serve as the sole lookout in clear weather. Under Rule 5, this arrangement is:

   • A.Potentially acceptable in certain circumstances but requires careful assessment of conditions✓
   • B.Always acceptable as long as radar is operational
   • C.Never acceptable under any circumstances at sea
   • D.Acceptable only in waters where a vessel traffic service is operating

   Why: While Rule 5 requires a proper lookout at all times, the IMO has acknowledged in guidance that in certain circumstances, such as clear conditions with good visibility, the helmsman may serve as the lookout. However, this requires careful assessment and the OOW must remain vigilant. The standard is full situational awareness, not a rigid crew count.

Frequently asked questions

What does a proper look-out require under Rule 5?

A proper look-out requires vigilance by sight and hearing, plus all other available means (radar, AIS, etc.) appropriate to the conditions. It must be maintained at all times — not just in poor visibility — and its purpose is a full appraisal of the situation and risk of collision.

Does Rule 5 require a separate look-out from the helmsman?

The rule does not specify a separate person, but good seamanship and case law establish that a helmsman cannot simultaneously act as an effective look-out on larger or busier vessels. In practice, a proper look-out often means a dedicated person who is not also steering.

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