Forepeak
The Forepeak is the compartment right forward in the bow of the ship, ahead of the collision bulkhead. It is normally a ballast tank — the forepeak tank — used to adjust the trim of the ship by putting weight forward, and in some arrangements it also houses the chain locker for the anchor cable.
Because it sits ahead of the collision bulkhead — the watertight bulkhead required near the bow — the forepeak also acts as a buffer space that helps limit flooding if the bow is damaged in a collision or grounding.
The forepeak is both a trimming tool and a safety buffer: filling or emptying it trims the ship by the head or stern, while its position ahead of the collision bulkhead helps contain flooding after bow damage. It is a small tank with an outsized role in trim and survivability.
What is the collision bulkhead?
A watertight bulkhead set a required distance back from the bow. The space forward of it — the forepeak — is designed to limit flooding into the rest of the ship if the bow is holed.