a structure used in underwater work, consisting of an airtight chamber, open at the bottom and containing air under sufficient pressure to exclude the water.
2.
a boatlike structure used as a gate for a dock or the like.
3.
Nautical.
a.
Also called camel, pontoon.a float for raising a sunken vessel, sunk beside the vessel, made fast to it, and then pumped out to make it buoyant.
b.
a watertight structure built against a damaged area of a hull to render the hull watertight; cofferdam.
4.
a two-wheeled wagon, used for carrying artillery ammunition.