Question

is true or magnetic likely to be the most useful when navigating underway?

it does not matter because the gps can use both.

magnetic will generally be most useful because it coincides with your compass.

it does not matter because compasses are usually wrong anyway.

true will generally be most useful because it points directly to the north pole.

Explanation:

When navigating underway (e.g., on a ship or aircraft), compasses used for immediate, on - board navigation rely on magnetic north. Magnetic navigation aligns with the compass's readings, which are practical for real - time, on - the - move orientation. GPS can use both, but for the direct use of the compass (a common navigation tool underway), magnetic is more directly useful. The option saying compasses are usually wrong is incorrect as compasses are reliable for magnetic navigation. True (geographic) north is useful but not as directly applicable to compass - based underway navigation as magnetic north.

Answer:

B. Magnetic will generally be most useful because it coincides with your compass.