I have a 16' Sylvan aluminum side console with a 40 hp Merc classic two stroke. My boat is rated for 80 hp...no way would I want an 80 hp on the back...I can get 32 mph with just me and 28/29 with two and fishing gear. What is your definition of underpowered ? I mostly run lake erie, very rare is the day I can run wide open, typical cruising speed around 20-22 mph. I don't ski or do other water sports, just fish and joyride.
