Originally Posted by JWMBM3
A heavy load would be roughly 9-10 people with fishing and camping gear.
Would a 150HP on a 21 ft RIB be insufficient in terms of power for a load like that?
A friend of mine had a 150 on a 6.5m boat and he could take a group of 8 divers and all of their equipment and the boat was starting to feel quite sluggish when fully loaded (still OK though)
Personally, I would look at a slightly bigger engine with 10 people and a heavy load, and possibly a 4-blade prop to help the boat onto the plane
Think carefully about your boat setup and the load distribution too, with those sort of weights. You need to make sure that you can keep enough weight forward