What term describes a fast-moving boat that hops and sways violently?

The term that accurately describes a fast-moving boat that hops and sways violently is porpoising. This phenomenon occurs when a boat's bow rises and falls repeatedly, resembling the motion of a porpoise leaping out of the water. It typically happens at high speeds when the boat encounters waves or other conditions that disrupt its stability.

Chine hopping, while it involves a similar fast and erratic motion, specifically refers to when the boat's hull doesn't fully break the surface tension of the water, causing it to bounce side to side over the water surface. Pitching refers to the up and down motion of the boat's bow, but it doesn't capture the violent, alternating movements associated with porpoising. Rolling describes the side-to-side tilt of the boat, which is different from the specific hopping motion linked to porpoising.

Understanding these terms helps boat operators recognize and address different types of motion their crafts can experience, which is critical for maintaining control and safety while navigating.