A fire on the submarine is probably the most feared casualty and it is this premise on which I based my prank.
After a previous night's dinner of boat food and with 3 guys in Sonar, I cut loose a silent but violent fart that had been brewing for a while. As it escaped its dark prison I said with a straight but concerned face, "Does anybody smell smoke?"
Everyone started taking deep breaths to overcome the blanketing smell of "the boat" and see if they too could smell smoke. Everyone of them got a full nose full of my ass. They have so much to learn.