1) Nautical terminology 
A watertight box built against the hull of the ship communicating with the sea through a grillage, to which valves and piping are attached to allow water in for ballast, engine cooling, and firefighting purposes.
A watertight box built against the hull of the ship communicating with the sea through a grillage, to which valves and piping are attached to allow water in for ballast, engine cooling, and firefighting purposes. Also a wooden box used to store a sailor
A sea chest is a rectangular recess in the hull of a ship. The sea chest provides an intake reservoir from which piping systems draw raw water. Most sea chests are protected by removable gratings, and contain baffle plates to dampen the effects of vessel speed or sea state. The intake size of sea chests varies from less than 10 cm² to several squ...
a valve on the hull of the ship to allow water in for ballast purposes.
[n] - a sailor`s storage chest for personal property
noun a sailor`s storage chest for personal property