Lesson in physics: You (nor us) cannot determine what you need in a prop because you have not yet determined if there is an actual problem. What you have may have been optimized and anything you do can actually harm performance. As suggested, dunk the boat, run it wide open throttle with what you consider an average load. If the engine cannot reach or get close to the upper end of the recommended RPM limit, you would need to go down in pitch. If it tends to over rev with that load, you can go up in pitch. But before looking for props, make sure the engine is in perfect operating condition. Changing props is a waste of money on an engine that is down on power do to age, wear, abuse, or poor state of tune. A water logged boat has an "overweight" issue and affects performance as well. A different prop cannot fix these issues..