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

The semi-displacement hull is specifically designed to combine the characteristics of both displacement and planing hulls. A displacement hull is optimized for efficiency and stability at slower speeds, allowing it to glide through water with minimal resistance, while a planing hull can rise and skim over the water at higher speeds, reducing drag significantly.

The semi-displacement hull seeks to incorporate the benefits of both designs. At lower speeds, it behaves more like a displacement hull, providing stability and comfort, while at higher speeds, it achieves some planing characteristics, allowing for faster travel without the need for excessive power. This blend makes it versatile for various operating conditions, which is highly beneficial in scenarios faced by boat crew members.

In contrast, the other options do not accurately reflect the functional characteristics or design principles involved in a semi-displacement hull. A hybrid hull doesn’t specifically denote a clear relationship between displacement and planing, while the terms flat, regular, heavy, shallow, and deep don’t directly relate to the specific dynamics of hull design associated with displacement or planing features.