While I applaud the hard work that went into this mod, the propellers could not be less historically accurate. Submarine props are made of bronze (or brass) and do not corrode - they experience some damage due to cavitation; however they would never, ever, EVER look like the ones in this mod. A submarine running props like that would may such a huge racket that it would be detected over my daughters stereo. (props to the film for that line LOL)
Anyways...I am surprised with how everyone is fixated on historical accuracy that this kind of major flaw would not be noticed.
Again, props for the work, but crap for the props.