I have a Yamaha 250 on my fishing boat and was looking at another prop and found this Yamaha prop selector tool, it walks you through your boat type, engine size, and desired output (hole shot, speed, etc). After you select all the options it's gives you various Props for your need and boat type. you don't have to buy their props but it gives you several prop diameters and prop pitches to get you to your desired outcome.

Anyway just thought some of you may have an interest in this program.

https://www.yamahapropselector.com/propSelector/web/inner.html

Those are very general guidelines. Most boat manufacturers that have an engineering department and are reputable will have a detailed rigging chart for all their models with various engine HP options.
They will have done all the testing and can give you prop pitch, diameter, engine height, loading parameters, etc for each model.
Bear in mind that unless you are dealing with very expensive custom designed props…. That two identical props new in the box will usually run a boat differently.
Folks gotta decide what their performance goal is….. best top end, best hole shot, best cruising speed, etc.
Some props by design lift the bow or lift the stern, lift the whole hull, etc….
Mainly you want a prop that meets your individual goals for your boat but allows the engine to operate within its max rpm recommended range to correctly develop its rated horsepower.

This is great information, I will likely be getting a new prop in '24. Being a newbie boat owner this really helps.

Gunny456 said:

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Those are very general guidelines. Most boat manufacturers that have an engineering department and are reputable will have a detailed rigging chart for all their models with various engine HP options.
They will have done all the testing and can give you prop pitch, diameter, engine height, loading parameters, etc for each model.
Bear in mind that unless you are dealing with very expensive custom designed props…. That two identical props new in the box will usually run a boat differently.
Folks gotta decide what their performance goal is….. best top end, best hole shot, best cruising speed, etc.
Some props by design lift the bow or lift the stern, lift the whole hull, etc….
Mainly you want a prop that meets your individual goals for your boat but allows the engine to operate within its max rpm recommended range to correctly develop its rated horsepower.

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I used this tool to see what was the best hole shot prop for my boat … it selected a few props almost identical to the prop I run, a Bravo1 - 4 blade 23 pitch w plugs removed… It's really just a starting point, the boat manufacturer suggested the Bravo1 I use, I'm just buying a cheap backup prop to throw on the boat in case I get into trouble for some reason, this tool is plenty good for that, but it does allow amateurs Like myself to a place to start when looking at props … the Yamaha site also reminded me about possibly red lining with the wrong prop

I've played with the selector before. I noticed it isn't really set up for outliers regarding boat type, size, or some of the smaller outboard sizes, but it gives some ideas.

I find it best to run a cheap aluminum or painted steel prop and then use that performance as a basis for playing with pitch and diameter to get the right max rpm and performance profile.