It should work just fine for everything if it is the right manufacture. About any 8hp would work for in-line boards! It does not take much to move a boat 1 to 2 mph. and you would have some reserve power for trolling into the waves with in-lines. Can't say if it would work well into the waves with big boards though they pull alot harder than in-lines, IMO it probably would but that is only an opinion and not based on fact.