Mara River Air Boat Safari, Ltd.

Stripped down racing Airboats can reach speeds over 135 miles per hour on smooth, shallow water and can reach this speed in 4 seconds (1/8 mile), according to an article in U.S. Airboat magazine. Speeds over 60 mph in any watercraft is can be risky and is not recommended. The same is true for automobiles. The differences are: (1) Roads are much more uniform (and better lit) than waterways. (2) Unlike cars, most watercraft do not have brakes.

Stan Floyd, the president of the American Airboats Corporation, holds the official land speed record of 47.76 m.p.h. which was set in a standard American Air-Ranger at the Houston, International Dragway in September, 1995.

48 m.p.h. and an elapsed quarter mile time of 21.26 sec. doesn't sound that fast until you consider that it was set in a standard 300 h.p. 3-seat airboat not a stripped down hot-rod. The record was also set on asphalt. Going across a grassy meadow, this airboat could easily top 55 mph.

The key feature of an airboat is its all terrain capability, not its top speed. 45 mph on land, 60 mph on water, and 70 mph on ice is usually fast enough.

Can all Airboats go across land?

All AirRangers can but many airboats are under-powered or use mismatched engine-prop combinations resulting in poor performance on land. There is more surface friction on land so additional power (torque/thrust) is required. This is achieved four ways.

Are all Airboats ATV's? [all terrain vehicles]

No! (see definition) We at American Airboats believe that they should be and design our boats accordingly. The ability to hit 45 mph on dry land is one of the design parameters for an AirRanger.

Do Airboats have brakes?

Brakes are an extra cost item not included on a standard airboat. They are more common on airboats used on ice and consist of a hinged metal plate on the transom that flips down to increase drag. In the water, an airboat slows down rather fast when you back off the power and drop off the plane.

How are Airboats designated?

The most important designations besides manufacture are size and power. The popular AR814-H350 AirRanger is 8 ft. by 14 ft. and powered by a 350 horsepower automotive engine. 350 h.p. can be achieved with a 350 cu. in. engine using performance parts or an unenhanced 454 cu. in. engine. An AR820-H500 would refer to an 8 ft. by 20 ft. airboat powered by a 500 horsepower (502 cu. in.) automotive engine.

Do Airboats use marine engines?

Some do but the only marine part actually needed is a marine air filtration system. Automotive filters do not hold up in a marine environment. American Airboats routinely replaces exposed parts with more corrosion resistant ones but this is more cosmetic than absolutely necessary. Everything else is standard with the automotive industry. This means that if a fuel pump goes out, you can pick one up at the local auto parts store. (Not so easy with an aircraft engine).

The marine designation on an engine mostly refers to the cooling system which must be beefed up if it is to circulate salt water. Beefing up includes replacing the engine block drain plug with a corrosion resistant one.

Airboats have a closed cooling system exactly like a car so there is no need for fully modified marine engine.

Airboats typically use a high efficiency racing type aluminum radiator to reduce weight and increase corrosion resistance.

Do Airboats have transmissions?

Some people ask this question wondering if an airboat has a reverse gear. Others confuse the reduction drive with a gear box. An airboat has no way to change gears. The propeller, however, is not always bolted directly to the crank shaft.

Some airboats have reduction drives (usually belt drives) to achieve something close to a 2 to 1 reduction. The drive functions the same way that 2nd gear does in a car. Automotive engines must turn high revolutions (rpms) to achieve their peak horsepower. Aircraft engines achieve peak horsepower at low revolutions (about 2500 rpm).

Cars running in second gear will accelerate quicker and climb steeper hills. The same is true for an airboat with a reduction drive. The reason that people do not cruise in second gear is because it burns more gas and produces more noise. This is not necessarily true in an airboat application - it depends on the prop that is used. An engine with a reduction drive will swing a bigger prop (or a prop with more blades).

Most of the noise created by an airboat comes from spinning the prop over 3000 rpms. It is prop noise not engine noise.

A bigger prop turning lower rpms will produce the same thrust as a small prop at high rpms and produce less noise.

How do you get high torque (thrust) at low propeller RPMs?

There are four ways:
(1)	use a reduction drive, {usually a 2:1 belt-drive reduction}
(2)	install a cam that improves the engines low end performance (higher torque at lower rpms),
(3)	use a propeller designed to deliver high thrust at low rpm, and
(4)	use an engine designed to turn a propeller. (aircraft engine)

The most economical solution is to install a new cam in an automotive engine. The best solution is to use a high performance automotive engine with a reduction drive in combination with a high output adjustable pitch propeller such as the PowerShift.

Aircraft engines are great because they produce high torque at low revolutions (peak power at around 2800 rpm) but they can be very expensive to purchase and even more expensive to maintain. Any mechanic can fix a Chevy 454. An aircraft engine usually requires an aircraft mechanic.

Why is the prop in the rear?

Today, almost all airboats are rear prop pushers but it was not always the case. Rumor has it that the first airboats had the prop mounted in the front which quickly led to the invention of goggles and ear plugs :-)

For many reasons using a rear mounted engine and prop to push the craft worked much better the other designs.

Do all Airboats use aircraft engines?

Before 1980, 90% of the airboats were built with aircraft engines. 90% of airboats built since 1990 are built with automotive engines. The primary reason for this is ease of maintenance. Almost any mechanic can work on a Chevy V-8 and parts are readily available. This is not the case with aircraft engines.

To match the high torque and low rpm performance of an aircraft engine, an automotive engine must have a new cam installed or use a reduction drive.

Most American Airboats are fitted with either small small block 350 cu. in. or big block 454 cu. in. Chevy engines. Horsepower depends on performance options.

How many people can an Airboat carry?

An 9 ft. x 24 ft. tour boats are typically designed to carry 22 people. It has three 9 ft. bench seats which can hold about 6 people. In addition there are two jump seats on either side of the pilot.

The maximum load is a function of displacement (size and transom height). The number of passengers depends on size and seating arrangement. Some airboats can carry loads of 6,000 lbs. or more.

A Minnesota hunting and fishing guide requested a boat that would carry 6 passengers and 1000 lbs. of gear over water and obstacles at 45 mph for 800 miles. He made this request after tearing up his third water screw on an expedition 100 miles from the nearest phone. This type of accident would never happen in an airboat.

How reliable is an Airboat?

Airboats (using Chevy V-8 engines) are about as reliable as a Chevy truck. Eventually something breaks down but it is not that much of a hassle to repair. About the only problem that we have had that required the assistance of a rescue boat was a fuel pump failure. We now carry a spare fuel pump on all trips over 100 miles.

American Airboats have an edge on reliability due to the use of superior materials, better designs, superior welders and mechanics, and better quality control. Each boat receives and extensive quality and performance check before delivery. Most failures occur in the first couple of hours of operation so we take a day to water test and fully check out each boat.

The American aluminum hull is the industry standard for rugged reliability. Most of the other parts are purchased from suppliers. They can be purchased by any boat builders. Other than the hull, the difference between manufacturers is primarily a matter of vendor selection, buying the best components, correct assembly (which is related to the expertise of their workers and quality control), and fine tuning.

Who built the first Airboat?

Alexander Graham Bell, who carried out many experiments with aircraft and water craft after the success of his telephone, built an airboat in 1905 in Nova Scotia. The craft he and his engineers built was dubbed the "Ugly Duckling". The craft was primarily used to test aircraft engines and props. Some Cajuns in southern Louisiana claim their granddads built airboats using Model T engines and hand crafted props.

Where can an Airboat be used?

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. While airboats have been used as dive platforms for underwater exploration, they are not (as the cartoon indicates) a submersible.

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.

What is the definition of "Airboat"?

A buoyant self propelled multi terrain vehicle that depends primarily on air thrust for propulsion.

Does attaching a fan on a jon boat turn it into an airboat?

Not by this definition. There are watercraft being sold as "airboats" that are not ATVs.

Airboats do not use a submerged water screw and do not churn up the water. Except for the noise, airboats are very eco-friendly.

The airboat differs from the hover craft with respect to the amount of air cushion. An airboat may route some air from a supercharger to a cavity beneath the hull to reduce surface friction. The air cushion, however, is infinitesimal compared to a hover craft which often routes half of its power to the task of generating an air cushion.

Most airboats are about 16 feet in length but they have been built as short as 6 ft. and as long as 30 ft. There are drilling platforms, which are essentially air-screw powered barges, that are much bigger than 8x30. The 8 ft. width is about the maximum width for easy tailoring and trucking.

The term "airboat" is not found in most abridged dictionaries.

What are Airboats used for?

Airboats are used in a wide variety of applications where access (just getting there and getting back) is a problem. If the place you need to get to is in wetlands, shallow water, obstructed waterways, bogs, swamps, or in a pantanal, there are few other choices and none more cost effective than an airboat.

Airboats can carry heavy payloads across a variety of terrains without leaving scars on the land or polluting the waterways.

What kind of motor is used?

Early airboats used rebuilt aircraft engines. The flat 6 cylinder Lycoming was a popular power plant in the past. Today, the most popular power plant is a Chevy 350 cu. in. V-8. For overland use, a 454 cu in. Chevy or Ford is the most popular choice. Just about any engine can be used but they should be adapted to a marine environment. When an automotive power plant is used, it can be easily serviced by most any mechanic. Parts are also readily available. Engine comparison chart

How can you reduce the noise that an Airboat makes?

Noise is generally related to prop speed. One way to reduce prop noise is to reduce the spin rate or rpms that the prop turns to provide the needed thrust. This can be done several ways.

The lighter weight composite props deliver more power at lower rpm and produce less noise. This has been the key improvement in the last 5 years.

Many airboats (and most aircraft) have no mufflers. Adding a muffler will reduce the engine noise.

Many of the ways to reduce the amount of vibration and noise transmitted to the aluminum hull are proprietary. Some hull coatings will reduce noise.

How many Airboats are in use around the world?

We are working on this one. American Airboats are used in over 15 countries but we do not have an industry total. Photo of an airboat built for the Siberian tundra.

All F.A.Q. and answers are from American Air Boat's F.A.Q. section

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