In case of fire, obviously there are times when quick retreat is the only plan. If gasoline, propane, or even a can of WD-40 is likely to become involved, you need to go. Fiberglass ignites fast, so only incipient fires are worth fighting. Of course, if you are sailing and aware, this is the only sort of fire you should face. Thus, assuming the engine is diesel and the propane is shut off at the tank, which is also some distance away, you have a few minutes.