I had to laugh at this. One of the biggest adrenaline rushes I've had underwater was on my fourth or fifth dive, when we were in typical lousy summer viz, and out of the dark in front of me swam something BIG AND DARK. My heart jumped into my throat and my eyes got really wide and my breathing got fast for a moment . . . Until I saw the big, green Nitrox stickers on the double tanks. Whew!
The first few times I got buzzed by seals on night dives scared the CRAP out of me

Now I just get annoyed because the eat all the fish
