This is just a personal opinion, but your engine has a Wide Open Throttle rev range recommended by the manufacturer. Personally I'd keep going up in pitch with your max load of people/gear onboard til you're about 100-200 rpm above the minimum recommended RPM at WOT.
Then dump then on a beach for 10 mins and try it out solo at WOT and see what your revs are.
You shouldn't (in THEORY) be overreving set up like that and you should gain speed and use a bit less fuel.
Need spares,consoles,consumables,hire,training or even a new boat?
Please click HERE
and support our Trade Members.
Join up as a Trade member
or Supporter HERE