How much air pressure do I need in our paddle cat/shredder? Does anybody ever use a guage? Our boat is Hypalon and I usually get it as firm as possible, it paddles better that way. I top off with a cheap hand pump until it starts getting hard to pump. I know what I want it to feel like but it's still a guess on the actual pressure. Just curious how easy it is to over inflate one or is it even possible with a hand pump?  
Thanks,
Tim