According to Rule 5, all vessels are responsible for maintaining a proper look-out at all times – this includes one-man crews, unmanned crafts, and recreational boats.
The term look-out implies watching and listening so that he/she is aware of what is happening around the vessel. The emphasis is on performing the action, not on the person. Still, in all but the smallest vessels, the lookout is expected to be an individual who is not the helmsman and is usually located in the forward part of the boat, away from the distractions and noises of the bridge. While no specific location on a vessel is prescribed for the lookout, good navigation requires placement at the point best suited for the purpose of hearing and observing the approach of objects likely to be brought into collision with the vessel.
The size of the vessel and crew effect this answer, however, the emphasis in every legal decision points to the need for a proper, attentive look-out. While the use of radar to evaluate the situation is implied in the requirement to use all available means, that is still understood to be secondary to maintaining a look-out by sight and hearing.
