Airboat
An airboat is a flat-bottomed watercraft propelled by an aircraft-type propeller and powered by either an aircraft or automotive engine. It is commonly used for fishing, hunting, recreation, and ecotourism.
Airboats are a common means of transportation in marshy or shallow areas where a standard inboard or outboard engine with a submerged propeller would be impractical, most notably in the Florida Everglades but also in the Kissimmee and St. Johns rivers, and the Mekong River and Delta, as well as the Louisiana bayous and Mesopotamian Marshes.
Overview
The airboat’s characteristic flat-bottom allows for easy navigation through marshes and other shallow bodies of water, including flooded areas. A version is also adapted for use on ice.The lack of operating parts below the waterline makes the craft ideal for rescue operations.
The airboat is propelled by a column of air generated by a propeller, with wind speed generated up to. Rudders attached to a control stick divert the air to steer.
Airboats generally travel at speeds of around ; modified craft can reach.
Without special adaptations, airboats cannot go in reverse. Slowing and stopping an airboat is more difficult than a normal watercraft because it rides on top of rather than in the water.
The operator's seat is typically in an elevated position to maximize visibility.
In the United States, a typical good-quality airboat in 2004 cost between $33,000 and $70,000. In a developing country like Iraq, however, an airboat may be purchased for as little as 2.5 million Iraqi dinars, or $2,147.
Because of their specialized design and limited mobility beyond the conditions they are designed for, airboats represent a small fraction of total watercraft. As of December 2017 there were 12,164 airboats, 1,025 of which were commercial, in the state of Florida. Airboats are widely used in other Gulf Coast states, especially Louisiana.
Soviet airboats and aerosleds
Airboats and airboat-like craft have been used in the Soviet Union and its successor states since the Second World War and possibly earlier. Some true airboats—vessels that operated entirely in the water—were used by the Soviet military in World War II. These true airboats include the NKL-5, a WWII armed boat reportedly capable of speeds up to. However, most Soviet airboats are aerosleds. An aerosled is an aircraft propeller driven amphibious vehicle best described as a hybrid of a sled, airboat, and ground effect vehicle. Thousands of aerosleds were used as cargo and passenger vehicles in Siberia, where they cope excellently, working equally well in the icy Siberian winter and in muddy, marshy conditions of the Rasputitsa season, when meltwater and thawing snow makes travel by road impossible. Aerosleds are still in use today. The Tupolev A-3 Aerosledge is a quintessential example of this type of vehicle; it can reach speeds of up to on snow and on water.History
The airboat was invented in 1905 in Nova Scotia, Canada, by Alexander Graham Bell. It first saw military use in 1915, by the British Army in the World War I Mesopotamian Campaign. Expanded civilian use appeared in the 1930s.Prototypes
The earliest ancestors of the airboat were waterborne vehicles for testing aircraft engines. 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. Ugly Duckling was a catamaran-type boat driven by an aircraft propeller hooked up to a water-cooled aircraft engine weighing. The makeshift raft-like vessel was unable to move faster than 3.5 knots), 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.Brazilian aviation pioneer Alberto Santos-Dumont built a similar catamaran vessel for testing an aircraft engine in 1907, which he termed a hydrofoil.
The Tellier brothers, French aviation pioneers, made major steps towards modern airboats with their 1907 speedboat La Rapière II. La Rapière II was an long mahogany speedboat powered by a partially above water aircraft propeller hooked up to a 20 hp 4 cylinder Panhard-Levassor engine. The boat was steered by a conventional rudder in the water, which was hooked up to a ship's wheel. La Rapière II could achieve speeds of up to with two people on board and with 3-4 people on board. French financier, balloonist, and aircraft enthusiast Jacques Schneider, of Schneider Trophy fame, developed and experimented with his own multi-passenger brand of airboat circa 1913–1914.
Early airboats
The first airboats to see any real use date to 1915. The British Army used airboats, which they referred to as Lambert "Hydro-Glisseurs"," in the Mesopotamian Campaign of the First World War. 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. They were primarily used for reconnaissance on the Tigris River. The first of these airboats, HG 1 Ariel, was constructed using the engine and propeller of a wrecked Royal Australian Air Force Farman MF.7 biplane and was provided to the forces in Mesopotamia by the British Raj. Following ArielFollowing the war, Lambert airboats were used as ferries on the shallow waters of the upper Yangtze River, on the Huangpu River, and elsewhere. Like their military counterparts, these airboats were manufactured in France, though they were assembled in Shanghai. They had drafts of only seven inches and could cruise at up to. Lambert airboats were also used widely on the upper Missouri River and on the marshes of the Florida Everglades.
Farman Aircraft, the company that built the engines for the WWI military airboats, began producing civilian airboats in the 1920s. 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.
File:Vintage Farman airboat.jpg|thumb|Farman airboat prototype Le Ricocheur in 1924. She was capable of speeds of up to 125 km/h
These early European airboats were significantly different from their modern counterparts. Compared to the airboats of today, early European airboats tended to be somewhat larger, had higher freeboards, and lacked a protective cage surrounding the propeller. They also had a different steering mechanism: early airboats were steered with a rudder in the water controlled by a steering wheel with throttle control provided by a gas pedal, like an automobile. More modern airboats use an air rudder controlled with a joystick for steering.
Early American airboats
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.Airboats began to become popular in the United States in the 1930s, when they were independently invented and used by a number of Floridians, most living in or around the Everglades. Some Floridians who invented their own airboats include frog hunter Johnny Lamb, who built a 75-horsepower airboat in 1933 he called the "whooshmobile" and Chokoloskee Gladesmen Ernest and Willard Yates, who built an airboat in 1935 they steered via reins attached to a crude wooden rudder. 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.
An improved airboat was invented in Utah in 1943 by Cecil Williams, Leo Young, and G. Hortin Jensen. Their boat, developed and used near Brigham City, Utah, is sometimes erroneously called the first airboat. 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. Their airboat had no seat, so the skipper was forced to kneel in the boat. They dubbed it the Alligator I as a response to a joking comment from US Fish and Wildlife Service headquarters that they should "get an alligator from Louisiana, saddle up and ride the critter during their botulism studies." Their airboat was the first to use an air rudder, a major improvement in modern airboat design.
The purpose of Williams, Young, and Jensen's airboat was to help preserve and protect bird populations and animal life at the world's largest migratory game bird refuge. The Bear River Migratory Bird Refuge near Brigham City, Utah, is a wetlands oasis amid the Great Basin Desert and an essential stopping point for birds migrating across North America. 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". Designs and subsequent improvements and practical use of the air thrust boats appear to have been a collaborative effort. LeeRue Allen, who worked at the Refuge since 1936, appears to have also been involved and helped to document a history of the events.
Many of the early airboats built at the refuge in Utah were shipped to Florida. Early records show it cost roughly $1,600 to build a boat, including the engine.
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.
File:Hydrilla verticillata collection LakeSeminoleFL.jpg|thumb|upright|The US Army Corps of Engineers uses an airboat to collect herbicide-resistant hydrilla from Lake Seminole in northern Florida