Martin JRM Mars

The Martin JRM Mars is a retired large, four-engined cargo transport flying boat designed and built by the Martin Company for the United States Navy, and the largest Allied flying boat to enter production during World War II, although only seven were completed. It grew from the PBM Mariner patrol bomber as the internal Model 170, and the prototype XPB2M-1 made its first flight on 23 June 1942 before the design was turned toward long-range transport. The Navy used the type on the San Francisco to Honolulu route until 1956, when it was withdrawn and stored. Four survivors were later converted into civilian firefighting water bombers, one of which, Hawaii Mars, served until 2016, and none remains operational.