The semi-displacement hull is a combination of characteristics of the displacement hull and the planing hull.

The semi-displacement hull is a combination of characteristics of the displacement hull and the planing hull.

• A. Displacement hull and Planing hull; Many Coast Guard boats are this type.
• B. Displacement hull and Deep-V hull; Many fishing boats are this type.
• C. Planing hull and Semi-displacement hull; Many sailing boats are this type.
• D. Semi-displacement hull and Displacement hull; Many racing boats are this type.

Answer: (A)

A semi-displacement hull blends traits of both a displacement hull and a planing hull. At lower speeds it behaves like a displacement hull, moving water aside and carrying a load with good stability and fuel efficiency. As speed increases, it begins to rise up onto a lighter running surface and gains more speed from planing lift, but not to the extreme of a full planing hull. This combination gives a useful balance of seakeeping, payload capacity, and speed, which is why Coast Guard patrol boats are often built this way—they need reliable performance in rough water without the heavy power demands of a full planing hull. The other options don’t fit because they pair the semi-displacement idea with hull types or contexts that aren’t characteristic of how semi-displacement hulls are described or used.

A semi-displacement hull blends traits of both a displacement hull and a planing hull. At lower speeds it behaves like a displacement hull, moving water aside and carrying a load with good stability and fuel efficiency. As speed increases, it begins to rise up onto a lighter running surface and gains more speed from planing lift, but not to the extreme of a full planing hull. This combination gives a useful balance of seakeeping, payload capacity, and speed, which is why Coast Guard patrol boats are often built this way—they need reliable performance in rough water without the heavy power demands of a full planing hull. The other options don’t fit because they pair the semi-displacement idea with hull types or contexts that aren’t characteristic of how semi-displacement hulls are described or used.