Designed to land on open ocean, the Grumman Albatross is basically an amphibious flying boat. Its deep V-hull and length, with a wing span almost 97ft, allow it to land, incredibly, on 4-foot seas, and even in more severe conditions (twice that with the help of booster rockets during takeoff).
Most albatrosses were used by the U.S. Air Force for primarily search and rescue missions, and generally considered a hearty and reliable aircraft for combat and non-combat use. During the Korean War, the albatross was used for open-water rescues of downed aircrew, including retrieving pilots from rivers on enemy lines. In total, over 1000 UN personnel were rescued.
By the Vietnam War, its long-wing variant, the HU-16B, was more commonly used. It was an albatross equipped with the latest naval technology of sonars and sonar-based bombs for the detection and destruction of submarines--essentially an anti-submarine aircraft. Instead, however, the HU-16B was mostly used for search and rescue operations, mainly by the U.S Air Force.
After the U.S.A.F., the U.S. Navy and over a dozen other foreign countries purchased them, such as the Chilean Air Force under the NATO Exchangen during the Cold War. Only a few are currently operating under civilian use, and, because of its heavy weight, weighing over 12,500 lbs, requires a type-rating.