Final answer:
A look-out should report objects sighted using relative bearings, which are based on the angular distance from the bow of the ship or nose of the aircraft, from 0° to 359°.
Step-by-step explanation:
In context of maritime or aviation navigation, when a look-out reports objects sighted, they should use relative bearings. A relative bearing is expressed as the angular distance from the bow of the vessel or the nose of the aircraft, moving clockwise from 0° (dead ahead) to 359°. It is different from a true bearing, which is measured with respect to true north, magnetic bearings, which are measured with respect to the Earth's magnetic north, and gyro bearings, which are measured with respect to a gyrocompass.
The correct answer to the question 'A look-out should report objects sighted using ____________.' is D. relative bearings.
For example, if a look-out notices a lighthouse while facing the front of a ship and the lighthouse is positioned to the right, at a perpendicular angle to their perspective, they would report that the lighthouse has a relative bearing of 090°. If the lighthouse were directly behind them, they would report a relative bearing of 180°. This system allows for quick and accurate communication of an object's position relative to the vessel's current direction.