calculator

All, Does anyone know of a good sailboat value calculator? I looked online and didnt see a good one. Thats all, Have a great week. Wes Zimmerman 1975 E29 Sailscall Grand Lake Oklahoma:cheers: :cheers:

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?:confused: