Yeah, those things ALWAYS give me the creeps...when I was taking my cert course, we would have to fill tanks occaisionaly. Most people would walk around in front of the tanks while filing tanks...I forget how many we could fill at once...but it was several. I always stood off to the side and tried to hide behind the racks that held the fill tanks...lol...people made fun of me. while we were in the Keys for a couple weeks of diving, we met a guy who had a tank explode on him in a shop. The scars were HORRENDOUS! He had pics showing the wounds, and what was left of the tank...I saw a LOT fewer people standing right in front of tanks as they filled, and more cowering in my "hiding spot". Has anyone heard any statistics of C02 tanks exploding? Makes me not really want a potential BOMB in the back of my rign.