reserve buoyancy

American  

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.

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Etymology

Origin of reserve buoyancy

First recorded in 1900–05

Example Sentences

Among other things, the boats’ metal frame and heavy chassis and transmission combined with the lack of reserve buoyancy means they sink quickly, and their low freeboard means passengers have little time to escape in an emergency.

From Washington Times

Their metal frame and heavy chassis and transmission combined with the lack of reserve buoyancy mean they sink quickly.

From Washington Times

We also reported then that the boats needed “reserve buoyancy,” such as foam or bulkheads, to help them stay afloat in adverse conditions.

From Washington Times

The N.T.S.B. said it had pushed for the Coast Guard to require duck boats to have more watertight spaces above the waterline, known as reserve buoyancy, and to remove obstructions such as overhead canopies that could hamper an evacuation.

From New York Times

The recommendations included removing overhead canopies that could trap passengers as the boat sank and implementing a reserve buoyancy mechanism to keep the boats from sinking at all.

From Seattle Times