The primary thing is to remember to swim towards the shore as you are getting out of the water. Stay flat and continue to belly crawl until you are well clear of the hole. One of the other threads mentioned Les Stroud. He did an episode on this exact topic. The episode was a controlled experiment. He was working with an expert in this area. It was a very good episode. When he fell in the water you could see actual, no kidding panic in his eyes. Look for it somewhere. Well worth watching. BTW, he didn't use ice picks.