Airboat
The airboat’s characteristic flat-bottom allows for easy navigation through marshes and other shallow bodies of water, including flooded areas.
[citation needed] Airboats and airboat-like craft have been used in the Soviet Union and its successor states since the Second World War and possibly earlier.
These true airboats include the NKL-5, a 1,200-kilogram (2,600 lb) WWII armed boat reportedly capable of speeds up to 60 kilometres per hour (37 mph; 32 kn).
The first airboat was the Ugly Duckling, an aircraft propeller testing vehicle built in 1905 in Nova Scotia, Canada, by a team led by inventor Alexander Graham Bell.
The makeshift raft-like vessel was unable to move faster than 3.5 knots) (approximately 4 miles per hour), though its propeller rotation speed led Bell to believe that the vessel had a theoretical top speed of "thirty or forty miles an hour," comparable to some modern airboats, if drag was completely eliminated.
[17] Brazilian aviation pioneer Alberto Santos-Dumont built a similar catamaran vessel for testing an aircraft engine in 1907, which he termed a hydrofoil.
La Rapière II was an 8-metre (26 ft) long mahogany speedboat powered by a partially above water aircraft propeller hooked up to a 20 hp 4 cylinder Panhard-Levassor engine.
These "Hydro-Glisseurs" were small, flat-bottomed hydroplanes with metal-clad wooden hulls propelled by a large aircraft fan that allowed them to reach speeds of up to 55 miles per hour (48 kn).
It marketed airboats for use as water taxis and as light cargo vessels or patrol boats for French colonial governments.
Its airboats sold for 25,000 to 50,000 francs depending on the model, a price that proved too steep for potential buyers; the company pulled out of the boat business by the end of the 1920s.
Glenn Curtiss is credited with building a type of airboat in 1920 to help facilitate his hobby of bow and arrow hunting in the Florida backwoods.
The millionaire, who later went on to develop the cities of Hialeah and Miami, combined his talents in the fields of aviation and design to facilitate his hobby, and the end result was Scooter, a 6-passenger, closed-cabin, propeller-driven boat powered by an aircraft engine that allowed it to slip through wetlands at 50 miles per hour (43 kn).
[14][15] Willard Yates holds the ignominious distinction of being the first person to die in an airboating accident, when the engine dislodged and sent the spinning propeller into him.
At the Bear River Migratory Bird Refuge in northern Utah, Cecil S. Williams and G. Hortin Jensen sought a solution to the problem of conducting avian botulism studies in the shallow, marshy hinterlands.
By installing a 40-horsepower Continental aircraft engine, purchased for $99.50, on a flat-bottomed 12-foot long aluminum boat, they built one of the first modern airboats.
The need for a practical way to navigate a challenging environment of wetlands, shallow water, and thick mud helped inspire Williams, Young, and Jensen to create the flat-bottom airboat, which they initially called an "air thrust boat".
[29] Over the years, the standard design evolved through trial-and-error: an open, flat bottom boat with an engine mounted on the back, the driver sitting in an elevated position, and a cage to protect the propeller from objects flying into them.
[6] According to a 2017 analysis by the Miami New Times, 64% of airboat accidents occurred due to operator error, attributable to one of three factors:[6] The engine[citation needed] and propeller of an airboat are enclosed in a protective metal cage that prevents objects such as tree limbs, branches, clothing, beverage containers, passengers, or wildlife, from coming into contact with the propeller.
[8][6] Airboats are top-heavy, unstable, and extremely shallow draft, making them prone to capsizing and sinking, particularly in the open sea or in rough or stormy conditions.
[37] Florida state law also stipulates that airboats must have an "automotive-style factory muffler, underwater exhaust, or other manufactured device capable of adequately muffling the sound of the engine exhaust", and an international orange flag that is at least 10" by 12" flying from a mast or flagpole that is at least 10 feet taller than the lowest point on the boat, in order to increase visibility and reduce collisions.
[40] Thirty airboats crewed by civilian volunteers evacuated over 1,100 patients and 4,000 medical personnel and family members from four downtown New Orleans hospitals in less than 36 hours.
During the Vietnam War the Hurricane Aircat airboat was used by U.S. Special Forces and South Vietnamese troops to patrol riverine and marshy areas where larger boats could not go.
[49] Two of these airboats were also used by the Khmer National Navy after they were captured from the U.S. Special Forces by the People's Army of Vietnam (PAVN) in September 1967.
[53] Modern Iraqi military airboats are 18 feet (5.5 m) long, powered by 454 hp engines hooked up to 78-inch (2.0 m) Whirlwind propellers, and armed with M240 crew-served machine guns.
In 2013 the Iraqi Ministry of Oil purchased 20 airboats for use as personnel transport, patrol, and cable laying and light cargo boats in the rivers and marshes of Iraq.
