11/15/2014. Remarks by Johan Visschedijk: "The PM-1 was the production version of the Naval Aircraft Factory PN-12. It was a twin engine biplane flying boat of metal and fabric covered metal construction with two 525 hp Wright R-1750D engines and it had a crew of five. Armament consisted of single 0.30 in (7.62 mm) machine guns in the bow and dorsal positions, while four 230 lb (104 kg) bombs could be carried under the wings. Throughout their service life they picked up such minor refinements as ring cowlings and enclosed pilots' cockpits.

The Bureau of Aeronautics issued a contract for thirty PM-1s (BuNo A-8289 to A-8313, A-8477 to A-8481) to the Martin Company on 31 May 1929. On August 21, 1930, VP-8S was the first squadron to receive the PM-1, while VP-16 was the last squadron to report the PM-1 in its inventory on April 30, 1938.

Under the BuNo A-8662 to A-8686, 25 PM-2s were ordered, this was an improved version with larger ring-cowled 575 hp Wright Cyclone R-1820-64 engines. The PM-2 was distinguished by twin vertical tail surfaces."