just a thought and maybe in the future some day this mite be possible .
how about 2 light weight electric motor's that run off a single diesel generator " this would be a green idea "
of course the electric motor's will need to push around 1500 lbs + TQ and run at 6ooo rpm's + to push something in the 45 to 50 foot range with some speed .
iv herd that electric motor's have a lot of TQ and can also push high rpm's , the hard part is making them light .
I think some of the big cruise ship's run this type of set up to be more efficient " green "