My dive buddy and I decided to purchase dry suits recently. I got a DUI 450 CLx, which I love, and he got a O'neil neoprene suit of some sort. Its rear entry with neoprene seals. Problem is that it fills with water whenever he dives. The suit floodes via the neck seal. The seal is tight on his neck and he folds it over like your supposed to. The seal holds until he turns his head to looks to his side and then water poors in. Any ideas? I offered to wrap duct tape around his neck until it sealed but for some reason he wasn't interested.