US Patent 7237410 Surfboard lock

A surfboard lock is described being of unitary construction and including a lock body including two engagement members; the engagement members are movable from a retracted position to an extended position and may be locked in the extended position; in the retracted position the engagement members may be at least partially introduced into the finbox opening of a surfboard; in the extended position the engagement members may engage with the internal walls of the finbox opening to resist removal of the lock therefrom; and attachment means affixed to the lock body for attaching the lock to a sturdy object.