The Martin P6M SeaMaster, built by the Glenn L. Martin Company, was a 1950s strategic bomber flying boat for the United States Navy that almost entered service, production aircraft had been built and Navy crews were undergoing operational conversion, with a service entry about six months off, when the program was cancelled on August 21, 1959. Envisioned as a way to give the Navy a strategic nuclear force, the SeaMaster was eclipsed by the Polaris submarine launched ballistic missile.
All of the aircraft were scrapped. Some tail sections were retained for testing, and one of these is now in the Glenn L. Martin museum, along with some wingtip floats re-used by a Martin employee to build a catamaran.
Martin tried unsuccessfully to market the technology in the civilian market but there were no takers, and the company soon abandoned the aircraft business entirely to focus on missiles and electronics. The P6M was the final aircraft constructed by the Glenn L. Martin Company.