I built this airboat in 1993. It's 13 ft 6" long. It has a Lycoming O-360. I use it exclusively for cruising on the Willamette and Columbia rivers in the Portland Oregon area and exploring all the backwaters/swamps in the area. I have a few videos on YouTube. Just search for "airboating in oregon" or James Backstrand. The fastest I have had it going is 93.3 mph on the gps.