CaptK: Thanks for your input and the site that labels all the boat parts, really helps when explaining things
knottybouyz: I'd like any info you have on the subject if it's not a problem.
Coot: the main advantage I can see is that it would produce more energy than a tiny little windmill just mounted on the back of a boat.
Like I said, it may not be worth the trade off in size, weight, or cost, like it was stated earlier, too many unknowns.
There are many other designs other than the Derrieus Turbine obviously, it was just the first that sprung to mind as a result of the movie.
It just seems to me there should be some way to make use of the mast while not sailing.
at the very least maybe something small mounted on the top of the mast.
Again, it's just an idea.