how do you know what a good size of drift sock is for a boat? i have a 18' 06" aluminum Monark that is a pretty heavy boat and I'm looking to buy a drift sock for bumping bottom for catfish and using it for sauger fishing in the winter. I live in clarksville tn and fish the Cumberland alot . so if you ever been on the Cumberland river below the dam you know its steady sometimes and not so steady current sometimes. any input form anyone?