My buddy and I got into the middle of a bunch of these on the Ohio near Paducah 2 years ago. We were bass fishin, throwin traps/cranks but still managed to snag a couple and keep them on for 2-3 minutes. It was wild... we could hear them thumping into the bottom of his Ranger and had a few almost jump in the boat with us. The ones we saw were in the 10-15 pound range.
CC