What is the definition of "specific gravity" in dive physics?

Specific gravity is defined as the ratio of the density of a substance to a reference density, typically that of water at a specified temperature. This concept is crucial in dive physics, as it helps divers understand how objects will behave in water compared to the surrounding medium. The specific gravity of a material indicates whether it will float or sink when placed in water; if the specific gravity is less than 1, the material is less dense than water and will float, while a specific gravity greater than 1 means the material is denser and will sink.

Understanding specific gravity is vital for divers, as it influences buoyancy, which directly affects how well they can maneuver underwater and conserve energy. Other options mentioned may relate to aspects of buoyancy or displacement but do not encapsulate the precise definition of specific gravity, which is fundamentally about the density comparison rather than mere weight or volume measurements.