Which statement best describes a semi-displacement hull?

Which statement best describes a semi-displacement hull?

• A. Pure displacement hull
• B. Fully planing at high speed
• C. Submersible hull
• D. Combination of planing and displacement hull; doesn't truly get on the plane. Found on medium-sized small boats such as the MLB or UTB

Answer: (D)

A semi-displacement hull blends features of both displacement and planing designs. It’s designed to cruise faster than a pure displacement hull while not fully rising onto a planing surface. At modest to moderate speeds, the hull lifts enough to reduce drag, improving efficiency, but it doesn’t truly plane, so a portion of the hull remains in the water for stability and load-carrying capability. This gives a practical middle ground: better performance than a pure displacement hull without the demands of full planing speeds or the ride characteristics of a fully planing hull. That’s why the description of combining planing and displacement and not truly getting on the plane is the best fit. These hulls are common on medium-sized boats that need a balance of speed, handling, and capacity.

A semi-displacement hull blends features of both displacement and planing designs. It’s designed to cruise faster than a pure displacement hull while not fully rising onto a planing surface. At modest to moderate speeds, the hull lifts enough to reduce drag, improving efficiency, but it doesn’t truly plane, so a portion of the hull remains in the water for stability and load-carrying capability. This gives a practical middle ground: better performance than a pure displacement hull without the demands of full planing speeds or the ride characteristics of a fully planing hull. That’s why the description of combining planing and displacement and not truly getting on the plane is the best fit. These hulls are common on medium-sized boats that need a balance of speed, handling, and capacity.