I've got a 75lb mushroom anchor that is stuck on an a muddy/sandy bottom in about 12-25 ft (depending on tide) of ocean water in a bay. I attached the chain to a 12' alum. boat with a 9hp motor and could not pull it free of the bottom (went around in circles a lot). We even attached the chain to the boat an hoped that the up and down action of waves would pull it free...no luch. Any advice from someone who knows how to haul a mushroom anchor for the winter?? There is no rope, it's all chain.