A compartment located under the windlass where the anchor chains are stowed. It is usually subdivided inside by a longitudinal bulkhead. Chain locker is to be made watertight to the weather deck. The arrangements are to be such that accidental flooding of the chain locker cannot result in damage to auxiliaries or equipment necessary for proper operation of the vessel nor in successive flooding into other spaces. Where means of access into the chain lockers are provided, they are to be closed by a substantional cover secured by closely spaced bolts. Doors are not permitted.