Maybe a completely inappropriate subject so not sure if thread will be shut down. Just something I've always been cuirous about, Happened in last night's repeat of "Castle" when Beckett and Castle were in a car, pushed into the Hudson river and proceeded to sink. Eventually escaped, obviously since they're the main characters, by finding Beckett's gun and shooting out the windows, even though gun had been underwater and the car was nearly 100% filled with water. Will a gun fire underwater? Or is this just a movie/TV plot device used for convenience? Don't you need gaseous oxygen to make a spark and fire a bullet? Underwater that's obviously not available.