Amphibious helicopter An amphibious helicopter is a helicopter that is intended to rest and take off from either land or water . Amphibious helicopters are used for a variety of specialized purposes including air - sea rescue , marine salvage and oceanography , in addition to other tasks that can be accomplished with any non - amphibious helicopter . An amphibious helicopter can be designed with a waterproof or water - resistant hull like a flying boat or it can be fitted with utility floats in the same manner as a floatplane . Development . Helicopters have taken a primary role in air - sea rescue since their introduction in the 1940s . Helicopters can fly in rougher weather than fixed - wing aircraft , and they can deliver injured passengers directly to hospitals or other emergency facilities . A practical amphibious helicopter first appeared in 1941 and the water - landing feature soon proved its worth . Non - amphibious helicopters were required to hover above the scene of a water accident and utilize a hoist but amphibious helicopters were capable of setting down on the water to effect a rescue more directly . Fitted floats . In 1941 , Igor Sikorsky fitted utility floats ( also called pontoons ) to the Vought - Sikorsky VS - 300 , making the first practical amphibious helicopter . In the 1940s and 1950s , some models of helicopter such as the Bell 47 and 48 and the Sikorsky R - 4 and R - 6 were fitted with utility floats so that they could rest on both water and land . Pontoons can be filled with air or they can be utilized for storage of fuel or supplies . In 1949 , Sikorsky produced the H - 5H with both wheels and pontoons . Boat hull design . The Sikorsky S - 62 Seaguard was the first amphibious helicopter made with a flying boat hull — the prototype flew in 1958 . Utilizing many components of the earlier S - 55 , the S - 62 proved the idea , and Sikorsky flew their S - 61 Sea King prototype in 1959 for the U . S . Navy , a model intended for anti - submarine warfare . Both the S - 62 and S - 61 were ready for delivery in 1961 . Sikorsky produced 1100 S - 61s , including some that were not watertight : a longer cargo - carrying version was given rear doors and a ramp . Sikorsky licensed other manufacturers such as Agusta , Mitsubishi and Westland to produce variants of the S - 61 . Amphibious helicopters came into their own in the 1960s when robust boat - hulled designs were produced in quantity for military and civilian operators . Amphibious helicopters paid dividends for rescue personnel who enjoyed greater safety and success during operations . Overwater operations that used non - amphibious helicopters relied to a higher degree on hoists , rescue basket s , and rescue swimmer s . Nevertheless , beginning in the 1970s , amphibious models were steadily replaced by helicopter models unable to land on water , because of high amphibious aircraft development costs . The last amphibious helicopter model used by the United States Coast Guard was the Sikorsky HH - 3F Pelican , retired in 1994 . Resting on the surface of the water with the rotor stopped , in conditions of brisk wind and mounting surface waves , a boat - hulled helicopter with stabilizing floats on either side is less likely to remain upright than a non - boat helicopter fitted with utility pontoons . Difficulty in lifting off can be encountered , especially when heavily loaded or in increasing seas . The Canadian Forces developed a technique called " water bird " for landing their CH - 124 Sea King s in water . Limited water capability . Helicopters can be designed to withstand limited contact with the surface of a body of water . The 1958 Vertol HUP - 2 was an amphibious development of the twin - rotor Piasecki H - 25 which strengthened its hull and replaced lower nose windows with tough aluminum . The HUP - 2 was provided with a pair of stabilizing outrigger floats positioned amidships . The HUP - 2 was able to taxi forward or backward on water , regardless of wind direction . The CH - 46 Sea Knight and its Canadian variant , the CH - 113 Labrador , can land on water and rest for up to two hours in calm water . The rear sponsons hold two of the three landing gear units as well as self - sealing fuel tanks . The helicopter began service with the United States Marine Corps in 1962 , and with the Canadian military in 1963 , and is used to carry cargo and combat troops . The Boeing CH - 47 Chinook was made sufficiently watertight to allow it to land on water for a short time in carrying out covert operation s and special military missions . Buoyancy was increased with sealed compartments inside sponsons which extended most of the way along each side of the fuselage . For extended water usage , Boeing offered a kit to enhance its water resistance . The Sikorsky CH - 53 Sea Stallion , first introduced in 1966 , is also capable of limited water landing . Roles . Amphibious helicopters have been used in a variety of roles , including transporting the US president .