Than you all for answers so far, specially to you Fast.
You have probably seen a few props in the water.
Kiwi: max engine power for them is 55 HP, mine is 75, so they are out.
I liked Gori's overdrive function, but some people told me it is not that practical.
I also liked Autoprop automatic pitch, but again heard a few not so good comments.
All props are a compromise. Fix prop on a sailboat must compromise between drag while sailing and propulsion while motoring.
Folding props do not have this drag problem (but must still fit into the opening available).
Flexofold sized the prop for my boat as 20x12 3blade.
I do not know if they took same size as stock Bene prop and just reduced drag or they optimized it for better motoring performance as well.
Autoprop sized it at 485mm (about 19 inch)
Prop calculator on
Sail Calculator Pro v3.53 - 2000+ boats
recommends 23.8 inch
Of course I trust Flexofold sizing more then a free internet calculator, but still - it is a big difference between 20 and almost 24 inches.
Flexofold shows this article on their site: http://www.flexofold.com/upload_dir/...onthly_low.pdf
Any more ideas?