Originally Posted by dabnis
For starters you could run a course with a GPS and compare it with the projected hull speed, taking into account how dirty the bottom and/or prop is.
After that you could tow something like a small drogue to try to simulate head wind and/or heavy chop and see how much the speed drops off. If that cuts the towing speed a lot, maybe by a third or half, maybe it doesn't have as much thrust as you want. Perhaps comparing the numbers to your previous boat might give you a starting point.
Not very scientific, but it would be a place to start
Forgot this, the Beta specs show 3,600 RPM. If you can,t get close to this the prop may be over pitched or dirty. Might be good to have a diver do a hull and prop cleaning before any testing?
betamarine - Engine View