2 blade or 3 blade propeller

[ddilman]

I need help deciding between a 2 blade or 3 blade propeller
for a Catalina 36 with a wing keel. Planning to do little
or no racing and I''m non experienced in docking.
How practical is the 3 blade when docking? And is it worth
the extra drag when sailing?
Thank You
Danny

[Jeff_H]

You probably do not need a three blade on a boat like the Catalina 36. The extrad drag is not worth it.If you do go three blade I would strongly suggest going with a maxprop, especially if you are not racing.

Jeff

[joepovey]

Some have suggested a 4-blade for close work.

Cheers!

[sailingfool]

Danny,
The chocie of two versus three blades is determined by the clearance between your shaft and the hull. Your comination of engine HP and boat displacement calls for a certain blade area to properly load the engine. There's no value to a three blade except the extra cost if a two blade of sufficient blade area fits with adequate hull clearance.

I'd discuss your choice with a propeller specialty shop although there must be plenty of Cat 36 owners available.

Why are you buying a prop - doesn't the boat have one? If you are replacing, it's akin to a crime to not buy a folding/feathering prop for a sailboat. A fixed prop is like dragging a small anchor around. We switched to a three blade MaxProp on our CS 36 a number of years ago and it has served us quite well - well worth the etra $$$. Contact http://www.pyiinc.com/ for advice although I notice Sailnet nows carries the maxProp. A plus of a feathering prop like MaxProp is that the blades work almost as effectively in reverse as forward. Our boat will back up almost like a car, minimal prop walk and great acceleration.
These props are expensive, but like most things you get what you pay for.

Good luck.