Don't know Jim. I would think that if I had two engines underwater, the diesel would be the last to give out. Course, it would not matter because I would have crapped myself and had my kids and all hunkered in a liferaft!! HAHA!!
Can you waterproof some of that? I guess one of my thoughts too was what a lightning strike would do? I have always preached that: A lightning strike does not mean it went down the mast. A strike anywhere in the vacinity is good enough to take out many electronics. Would it take out an engine?? Maybe not. Don't know. Just think it is really cool. It actually reduces the cost of the boat, increases the range (b/c you have more room for fuel & recharge is added in), and is better on the environment.