Hi all, am looking for some info'. I get a problem with ear-pressure pain when I try for any depth. holding the nose and blowing dose,'t help, what is this Frenzel technique? What exercises can one enploy to increase lung capacity? And , finally, I snorkell around rocks and gullies getting in is ok,out,is another matter. Are there any fins/flippers whereby you can detach (easily) the fin, and be left with the shoe portion? This would be great for climbing out and walking on sharp rock.:crutch.jopras