I was not very happy with the stock 2-blade prop on my Ericson 28+ with a Universal 5411. I filled in a questionaire at West by North.com and got a new Campbell Sailer that made a huge difference when beating into a strong wind and wave. Made about .3 knots dif. on calm water and about 3 knots in rough. I was so impressed with the prop that I just ordered another for our new to us Beneteau first 38. Cost was pretty reasonable $600 for the 5411 and $800 for the Perkins ( Cdn. $ multiply by .73 for U.S.$) They tailor the prop to your boat and engine/trans. combo.