"I LIKE AIR"I like compressed air, I think it's so keen,I use it a lot in my own submarine.I use it to blow ballast water away;if I'm forced to escape, I might need it someday.It doesn't catch fire and it doesn't explode;the refills are cheap and the tanks don't corrode.It's excellent stuff (and for those who might doubt it)remember: you wouldn't be breathing without it!If a tire on the trailer begins to get low,a shot from the tank and I'm back on the go.Dive MY sub without it? I won't even daresubmerge underwater without compressed air.A. Nonny Mouse