My 1997 Parker 1800 with a 115 Yamaha 2 stroke, carb version, full tank of fuel, myself and wife, bottom painted and a T-top, 35 GPS mph w/ 13x17 stainless prop at 5000 or so rpm. Flat water, no wind. Why would anyone go that fast? I cruise at 24 mph with full load. Good economy and handling.