Screw Anchor System Perfect for anchoring a PWC in shallow water, just off the beach. Screw the zinc-plated anchor into compacted sand or mud in 2 to 3 ft. of water. There's a giant nylon snap hook at each end of the 8 ft. long marine grade rope. Snap one to the screw anchor and the other to your PWC or small boat. A padded nylon storage case protects watercraft and dampens noise while stowed.