The Grumman J2F Duck is an American single-engine amphibious biplane designed in 1934 specifically for the Coast Guard. The second model in the series was the J2F 4-6. It was used by each major branch of the U.S. armed forces from the mid-1930s until just after World War II, primarily for utility and air-sea rescue duties. After the war, J2F Ducks saw service with independent civilian operators. Its first flight was 2 April 1936. A total of 584 J2Fs were built, including 32 J2F-4s.