On my last dive in Belize I apparently was diving with my inflator hose cross threaded on my BC. I did both of the dives without incident, but waiting on the line at the surface for my turn on the ladder I kept sinking no matter how much air I tried to add to my BC. I then noticed the hissing of the air leaking out. Always do a bubble check before your make your descent. Nothing bad happened, but it certainly could have.