Abstract: A device for quickly releasing a surfboard tether from a body strap. The tether and surfboard are normally connected by a plug and socket swivel connection. The device comprises a removable locking pin which, in its locked position, extends through openings in the socket and through a passage in the plug to secure the plug and socket connection. A resilient retainer acts against the socket body and the locking pin to normally retain the locking pin in its locked position. The locking pin is adapted to be pulled out of the passage and socket body against the urging of the resilient member to release the plug and socket, thereby disconnecting the leash from the body strap. In one embodiment of the invention the resilient member comprises an elastomeric band which is looped around the locking pin and the socket body and acts against a surface of the locking pin provided for that purpose to urge the locking pin into the locked position to hold the plug and socket in connection.