An underwater chain stopper and fairlead apparatus for offshore structures, drilling platforms, ships or other vessels. The apparatus comprises a mounting member, a fairlead member and a chain stopper member. The mounting member is attached to an underwater surface of the offshore structure or vessel and includes a bracket for coupling the fairlead member. The bracket may comprise a hinge allowing the fairlead member to pivot in an approximately horizontal plane. The chain stopper member is coupled to the fairlead member through a hinge which allows the chain stopper member to pivot with respect to the fairlead member in an approximately vertical plane. The chain stopper member includes a chain stopper flapper having a horseshoe shaped opening at one end. The other end of the flapper is connected to the chain stopper member through a hinge which allows the flapper to swing between an open position and a closed position. In the open position, the chain links for the anchor chain are allowed to pass by the horseshoe shaped opening on the flapper. The horseshoe shaped opening also includes a chain link seat which stops movement of the anchor chain through the chain stopper member when the flapper is in the closed position. The chain stopper flapper moves to the closed position under the force of gravity to provide a self-locking chain stopper. A latch mechanism is provided for latching the chain stopper flapper in an open position.