Without knowing the WOT of a specific engine there is now way possible to prop it correctly. 9 out of 10 times a factory prop is not correctly propped for your boat.
I'll disagree on last part due to being a relative statement. Would say that 11 out of 10 times factory props which are medium pitched performs excellent on light to mediium applications. On light ones will be at, or around max safe wot factory parameters and sometimes exceed max wot numbers.
Will depend if using max rated HP engine to a given lenght boat for that to happen. To be clear, I'm reffering to engines that comes with standard factory delivered props, on larger engines delivered without a prop this equation doesn't fit as you'll need to pick one as a starter.
What you need to do is : with current prop, you alone, with lightly loaded boat, well trimmed engine, correct engine/transom height go for a wot spin on flat calm n
o wind water cond and check achieved max wot numbers, then can go from there maximizing prop pitch to be near max wot safe numbers to suit your boating needs, adding extra weight, passengers max engine rpm will drop accordingly.
Happy Boating
