I need help. There are two places I have been unable to anchor so far. I have a Chene (?) anchor, it is the standard river fluke anchor that pivots but requires no chain. It is sized appropriately for my boat (box said up to 26 ft boat). I have a 20 ft SeaArk. I cannot hold in the lock and dam tailwaters. 1. Would a chain help to weight it down and get it to the bottom quicker and not fly under the boat in the current? 2. Even when I get it on the bottom upstream of me and let out lots of rope it still drags bottom in the mud. 3. If I get a little to the side of the dam in the eddies I can anchor but then I drift around in circles. I also cannot grab hold in an area that seems to have a mostly smooth rock bottom (underneath a towering river bluff). 1. What style of anchor might help here? Thanks!