btw, ednaout, hand padlers DON'T SWIM so they really can't tell you how it would happen!!!!
They're very easy to take off, you just hook the back edge on your rimor an arm, your pfd, whatever, and they pull of easily.
In my opinion hand paddling is easier than using a paddle, it's very intuitive & simple. The only thing they lack is the power to get you moving fast for a big hole you need to punch. Turning & bouncing off rocks & general low volume boating is very easy though.
The biggest downside to hand paddles is that it's a pain to help your buddies when THEY swim!! (you know, because they don't have hand paddles!)