CMTaylor, you can produce a GREAT surf wave with a direct drive. I personally run 350 in front pushed against the surf side wall, 500 in the rear across the back and 700 on the floor on the passanger side. The wave is thigh-to-belly-button high. It is a great time and we surf a LOT!
Here is a link to a video of my 87 SunSport wave and me ripping it up!