A vessel reduces speed without backing. The rate that her speed through the water decreases depends primarily on the __________.

Correct Answer: Option D — vessel's displacement

Inertia is directly proportional to mass. When engines are stopped, the vessel's kinetic energy must be dissipated through hull resistance. A vessel with greater displacement possesses more momentum, meaning it will maintain its speed through the water for a longer duration compared to a lighter vessel under identical environmental conditions.