Created to rival the Consolidated PBY Catalina aircraft, the PBM Mariner was designed in 1937. Following prototype tests, the U.S. Navy ordered 20 PBM-1 aircraft by the Martin Company. The abbreviation means Patrol Bomber, Martin Company. Leading up to and during World War II, a further five variants of the aircraft were built and were used to compliment the Catalina and PB2Y Coronado aircraft during the Battle of the Atlantic and in the Pacific, where bases were housed at Saipan, Iwo Jima, and Okinawa.
Following World War II, Mariners were used during the Korean War to fly on long patrol missions. The final Mariner, PBM-5A, was primarily used for air-sea rescue missions.
Image: 80-G-38921: PBM-3. Photographed by Glenn L. Martin Company, April 1943. U.S. Navy photograph, now in the collections of the National Archives.