Some new bling

We are now at KKMI in Richmond getting some work done in preparation for heading south later this month. One of the easier projects on the list was to replace the 20+ year old 3-blade MaxProp with a spanky new 4-blade MaxProp. In the last year or so I noticed some chatter developing from the old prop at low RPM and I figured it was enough of an excuse to get something fresh on there before we begin some extended cruising.

When we repowered with a Beta 50 a few years ago, the mechanics at BetaMarine West advised me that according to their calculations I won’t be able to get all 50 horsepower transferred to the water with an 18″ 3-blade prop without overloading the blades and they recommended that the 43 horsepower model was a better match on paper. At the time I figured that I’d eventually get a 4-blade prop, so I went with the 50, so now this new prop should complete the setup.

Stern view of prop showing blades perpendicular to water.
Blades turned for motoring

Sonrisa was the first boat I’ve had with a feathering propellor and I have to say I really liked the MaxProp from day one. It really is a neat piece of engineering where the individual blades are interconnected by a center gear and rotate 180 degrees so that when the engine shifts into reverse, the leading edge of the blades rotates to face the rear. Likewise when the engine is stopped and the boat is under sail, the blades ‘feather’ or turn parallel to the flow of water, significantly reducing drag. This results in .5 to 1 knot of extra speed under sail and very strong thrust in reverse under power which is very useful for maneuvering in a harbor.

Stern view of prop showing blades turned parallel to the water
Blades turned for sailing.

While the old 3-blade prop worked very well, I hope that the 4-blade will give Sonrisa a bit more traction when motoring against the wind and waves.

While the new MaxProp is a new design that is much easier to adjust than the old one, I’m happy that it was an exact fit on the existing shaft.

While it won’t stay so shiny for long, Sonrisa gets a chance to show off her new bling for a few more days in the boatyard.

Side view of prop