reserve buoyancy

noun

, Nautical.

1. the difference between the volume of a hull below the designed waterline and the volume of the hull below the lowest opening incapable of being made watertight.

Word History and Origins

Origin of reserve buoyancy¹

First recorded in 1900–05

Example Sentences

When full, we still have three hundred pounds reserve buoyancy, and would have to go ahead and steer down.

From Project Gutenberg