As you add cup, you raise the average pitch of the prop. A heavily cupped 10 pitch will turn more like a 12 or 13 than a 10. Just one thing to remember when buying a prop. Trying to turn a 12 pitch on that motor with 4 men in the boat, probably won't get on plane. That's why you need to tach the motor and try several different props. If you can't tach the motor and want to save time, consult an expert. I mean a REAL expert, like someone that makes a living propping hunting/fishing boats. A good prop shop is invaluable.
There are just too many variables to prop performance to pick a prop without using an expert.
You really are asking the question in the wrong place. I know there is a wealth of knowledge here, but, you need an EXPERT, unless you want to buy several expensive paperweights.
I am not slighting anyone or their prop knowledge, but when I raced, I used the absolute best racing prop guy in the country. He wasn't cheap, and he wasn't fast, but his props were. He was the most important factor in me winning US1 and setting EVERY World Speed Record in the Class. He is a race prop expert. There are experts in hunting/fishing props in our area, find one and use him. Feed him data before you expect results. Feed him reliable data. It does no good to prop your boat empty then to load it down as you describe. When I run boats to test props, I either get another guy to ride in the boat or I fill a 120 quart cooler with water and strap it down in the boat to simulate my hunting load.
The data an expert needs is:
Speed
RPM at WOT
Pitch
Blade design
Optimum RPM that your outboard makes the most horsepower and torque.
You can settle for whatever or you can do it correctly and get the most from your rig.
I run 3 different props:
1 is for marsh fishing, hole shot is a neck snapper-motor stays on 6200 rev limiter if I stay at WOT
1 is for river fishing, top end is excellent, hole shot not so great
1 is for "put up or shut up" has horrible hole shot and great top end on an empty boat
They look different and perform differently. There is no 1 fits all. If someone invents a prop that will do everything great, he will never have to work again.
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