It topped out pretty quick... The torque was insane, almost too much. We were able to pull deepwater starts with no problem... I bet we could've pulled 2-3 people with no problem.
If I were you, I'd consider a gear ratio with more top-end. We had to run our winch wide open... Which meant we floored it when the rider was ready. That made for a shaky start, and sore shoulders! With 18hp, you'll have enough power to pull off deepwater starts and high riding speeds... Which will allow you to run at half-throttle for those who like to ride slower.