Bandit 28 Pusher Fan 

This is the new Bandit 28 Airdrive from Lone Star Hovercraft. It's a small tiller-steered pusher fan that clamps onto the transom of most jon boats. Designed for the Predator 8 hp, Predator 13 hp, or Honda GX390.
With the Predator 13 hp, it generates 50 lbs of thrust, similar to a mid-sized trolling motor. On the 1436 demo boat in the video, we can troll at 2.5 mph with the engine idling for 7 hours on 1 gallon of gas! Visit www.banditairdrives.com for more info.
Note this drive is generally designed to be used as a trolling motor, though it is possible for it to plane out very small, lightweight boats. The main advantage over a conventional trolling motor is that there are no parts in the water, so it can't be damaged on rocks, sandbars, etc, and it doesn't disturb mud or vegetation in shallow water.