Final answer:
The lookout on a cargo vessel in good conditions and clear of hazards can be either the helmsman or the mate on watch.
Step-by-step explanation:
While on watch at sea on a 700-foot cargo vessel being hand-steered during daylight hours in good visibility and clear of any navigational hazards, the lookout may be either the helmsman or the mate on watch. This means that the responsibility for maintaining a proper lookout can fall to the person steering the vessel (the helmsman) or to the mate on duty at the time. Having an individual dedicated to overseeing the safety and navigation of the ship ensures that the vessel operates efficiently and is prepared for any unforeseen events or obstacles.