After having boats for well over 20 years, all with gas appliances and no problems, although one time we did come home to a smell of gas, we turned off all appliances opened the doors and windows to get rid of the smell and we found it was a loose connection to the gas bottles, rectified this and all was well. If there is a gas leak then surely as we did you can smell it. The only time I have heard of an explosion was actually when an idiot decided to change bottles with a cigarette in his mouth.