The term "surface effect ship" (SES) refers to a type of vessel that utilizes a combination of air cushion and water displacement to achieve high speeds and maneuverability. Synonyms for this term include "air-cushion vehicle" (ACV), "hovercraft", "hydrofoil", and "wave-piercer". Each of these terms describes a specific technical method used to achieve the SES's unique performance characteristics. A hydrofoil relies on underwater wings to lift the vessel above the water, reducing drag and allowing for high-speed travel. Hovercraft use a fan-driven air cushion to lift the vessel off the surface of the water, while wave-piercers are characterized by their sharp hull and bow design, which reduces drag and enhances stability at high speeds.