Prop size calculator

[Annapolis E-27]

Is anyone aware of any links with a calculator to figure the proper prop size for a given boat and engine. In my case I have an E-27 with a Yanmar YSB-8 and no tachometer. How do I calculate for the best efficiency of a given prop size, pitch, and number of blades?

 

[escapade]

go to the source

I've had very good luck talking to the guy's at Martec directly. They are the most knowledgeable people I've found regarding the prpper size & pitch. They will want to know if fresh, salt, or brackish water (it makes a real differance), weather cruising or racing or both, what you presently have and what your looking for. They have provided the correct information for my E27, E30+, and E34 which by the way were all different than factory original. But I'm also in fresh water which is less dense than salt water where the Ericson factory was. Hope this help's you.
Have fun & sail fast
Bud E34 "Escapade"

 

[JORGE]

Calculating or approximate

I currently looking into a Campbell propeller"(westbynorth.com) for my Yanmar (installing soon, after I fix a cockpit floor leak),
but there is a website which does lots of sailing calculations including a propeller sizing at bottom of page, but I think it's just an estimation.

http://www.image-ination.com/sailcalc.html