Depends where you are??
If you give a little more info perhaps we can help. For me here in Maine, with lots of tidal rivers and bays, the factory three blade is the best choice. I had one of those fancy (read espensive) folding props and speed wise it barely saved a an 1/8 - 1/4 of a knot. The big problem with these folders is vibration. Mine went back to the factory each winter for two years before I finally put the fixed three blade back on..If you sail in an area where the harbor is "right there" at the waters edge and you don't have to motor against currents or travel long distances to get to open water sailing then the factory two blade is fine. I'm sure others will try and talk you into spending 3k on a folding prop, but after doing it, and weighing the extra 1/8 - 1/4 knot advantage I have decided the vibration issues and potential damage to my drive line are not worth it.Again it depends where you are and what you plan on doing with the boat...http://www.pbase.com/mainecruisingMaine Sail