Abstract: A grapnel anchor having an elongated shank with a fixed arm at its lower end and several movable arms mounted on the elongated shank. Each movable arm is mounted on the shank by a polygonal hole in the center of the arm. The upper end of the shank is enlarged to prevent removal of the movable arms from the anchor's shank. The upper portion of the shank beneath its enlarged upper end is a cylinder sized to permit each of the movable arms to rotate about the upper cylindrical portion of the shank. The outer surface of the lower portion of the shank between its cylindrical portion and the anchor's fixed arm consists of several identical elongated rectangles which in cross section forms a regular polygon slightly larger than the polygonal hole in the center of the movable arms.