FROM THE AMERICAN AIRBOATS WEBSITE: "Airboats are (or should be) all terrain vehicles or ATVs. They can traverse water, tall grass, marsh, mud, tundra, dry ground, log jams, small boulders, dirt roads, snow, and ice."

"They have been run through grass lands, dense brush, ice jams, and over dikes. Highly abrasive surfaces such as cement roads can be traversed but not without some wear and tear on the hull. The more abrasive the surface, the more polymer that is added to the bottom of the hull. UHMW Polymer provides a “teflon” like friction reducing surface. Airboat hulls are typically clad in polymer 1/4 in. to 1/2 in. thick. Ice boats add polymer to the sides."

"The size of obstacle that can be surmounted depends primarily on the power of the engine. Aircraft engines are designed to produce high torque at very low rpms because prop tips break the sound barrier at about 3000 rpm. Once supersonic, the propeller loses efficiency and becomes very noisy."

"Automotive engines produce their peak power at rather high rpms (about 4000+ rpms). Airboats do not have transmissions but they can have reduction drives so you can run in the automotive equivalent of 2nd gear rather than 4th gear. So, one can decide to run in 4th gear or 2nd gear. To increase the effective power, a reduction gear is used so the prop spins at a lower speed than the crank shaft. An automotive engine often produces its peak horsepower at 5000 rpm. The most efficient prop speed is around 2,500 rpm."