Folding Prop Size?

[eje]

I'm thinking of replacing the 3 blade fixed 16x15 propeller with a 2 blade folding. I assume I would need a different size and/or pitch. Is the a general rule on what to replace it with?

[Fbfisher]

Contact the company from whom you intend to buy a folding prop, provide them with the necessary specs for your boat, and they will tell you what size you need. They will also tell you whether a two blade or three blade is appropriate for your boat.

[eje]

A lot of old used ones out there.
I did try one of the online selection calculators, but it recommended a very different prop than I've got & the boat mfg recommended. I'm sure it was a data entry error

[Off Trail]

FWIW when we switched to a Flexofold, the manufacturer's recommendation was the same diameter, pitch and blade count as our existing fixed prop. Not sure how true this is generally....

[Hesti]

It's not just dia., pitch and number of blades, it's also blade area. Not enough blade area and you can have cavitation and can have difficulties making way against wind and waves.

There is a book from Dave Gerr on props, but asking a manufacturer will get you there much faster ...