Plus 1 for soldering iron.I make a grid of about 9 small holes in a 3 by 3 pattern across the back of the calf. Drain's perfectly and quickly, and works even if bottom of suits folds under a bit. First time I did it in a Rip Curl Flashbomb was nerve wracking. But wetsuit that is 3 plus years old and worn 3 to 4 times a week and the holes have not gotten bigger. Rest of the suit showing it's age, but the soldered holes in the calf are fine.