I started running antennas inside in 1983. Having an antenna external on a sailplane was just ugly, I just continued doing it on my power airplanes as well. You are correct that external was pretty much standard though although there is no supporting data that it was any better.

Fuel for your boats. Without knowing your compression ratio, plug heat and load that is an unrealistic question. That being said, I do not Veiw myself as equally qualified in the boat world. You clearly have much more experience and I am one who places value on experience. There is not much you could tell me about R/C boats that I would not take at face value. When it comes to the details of high performance power boats I can easily admit that " I don't know what I don't know ". It's a shame that you seem to not value experience in the same manner but I suppose it's humanity's differences that keeps life interesting.