I have a 32nd P VIIC U-Boat with dual WTCs,sound,lights, and the other bells and whistles. I also have R/C helicopters,boats,cars, a monster truck and 5 airplanes. From owning and running all these "toys?" I can say this. If it has a screw on it, tighten it once in a while. If the screw can come undone and can cause you to destroy your machine, check it each time. If a wire comes loose and will cause you to lose your machine, double check it. Anything that you suspect isnt 100%, will fail. Those you think are OK, are not. Adding water to the equation just amplifys the possiblity of failure.If you say to yourself, there is no way water can get through there, it CAN. The one tool you leave behind because you will not need it, you will.Bottom line is figure out which failures would cause you to lose your sub or diable it. What ever they are, really concentrate on those areas and make them bulletproof.