The propeller for my Bison electric outboard motor was getting a bit beaten up looking so I thought I'd have a go at making one with the 3d printer and 123D Design CAD software.
It's not an exact copy of the original but pretty close and fits very well.
It might also fit other makes of outboard as I've seen others with very similar looking props.

Update 8/7/2016 :-

Firtsly, apologies for taking so long to provide an update for this.
After testing version 1 on water, it turned out to be a little under powered due to the blades being too thin so I've made another version of the blades which are slightly thicker and so more rigid providing better thrust.
I've also produced a third version which can be printed as one whole piece if you have a 200x200mm bed.
This version was made with the same center piece (or prop head) I drew with CAD software but the blades were produced using a 3D scanner to scan the original blades. The 3D scan is extremely accurate so the blades on this version are pretty much a perfect copy of the Bison prop blades.
The blades were then merged with the center piece in 123D Design to produce a final STL file of the whole prop.
If you attempt to print this version, you will of course need supports and I'd recomment at least 20% infill.
I did try scanning the whole prop but there was a bit too much detail in the center piece to get a usable model.

Update 16/8/2016 :-

Some minor tweaking of the whole prop version to get a better fit and less friction.
I would recommend this version if you have a large enough build plate as it is the closest to the original prop and provides much better thrust.