What term describes the weight of the volume of water displaced by a ship when afloat?

The term that describes the weight of the volume of water displaced by a ship when afloat is "displacement." Displacement is a crucial concept in naval architecture and hydrodynamics, as it determines how much water a ship displaces when it is sitting in water. The weight of this displaced water is equal to the weight of the ship itself when it is floating at equilibrium in water.

Understanding displacement is vital for various aspects of ship design and stability, as a ship must displace enough water to support its weight. This principle is grounded in Archimedes' principle, which states that an object submerged in fluid experiences a buoyant force equal to the weight of the fluid it displaces.

The other terms are related but refer to different concepts: "draft" refers to the vertical distance between the waterline and the bottom of the hull (keel) of the ship, which is important for determining how deep a vessel sits in the water. "Buoyancy" refers to the upward force exerted by the fluid that opposes the weight of the ship, allowing it to float. "Ballast" refers to materials added to a ship to lower its center of gravity and increase stability, thereby affecting its performance and handling in the water