Davis Rocker Stopper Boat Stabilizer [352]Rocker Stopper Boat Stabilizer Rocker Stoppers help dampen the rocking motion of boats at anchor. Simply tie Rocker Stoppers approximately 44 cm (18) apart, making a string of them, with a 5 10 pound weight attached at the bottom of the string. Hang one string off each side of the boat. Just four units per side are what it takes on most boats to 36. Be sure you hang them where they will always be underwater. Many people use mushroom anchors with their