[Sailor Steve]

Good points. My final answer is "I don't know". Reducing weight would obviously help a little, but hydrodynamic drag is the real limiting factor, and the fineness (length-beam) ratio isn't going to change, and that's the real cause of limitations to top speed. Your points about the engines and the batteries make sense. I have no idea how much actual increase you would get that way, but the engines are rated at 6500 hp and the electric motors rated at 2740 hp, which is 42%, which would not get a 42% increase in speed but might account for an extra two knots. But if that was really possible you probably wouldn't need a 'special ability' to do it, just a competent engineer. Game-wise, increased chance of a breakdown plus having your batteries drain at the same time might be a fair trade-off. One set of worries in exchange for another. Too bad these games don't take things like that into acccount.