A U.S. Navy Martin P4M-1 <i>Mercator</i> of Patrol Squadron 21 (VP-21) "Black Jacks" in flight in flight. VP-21 flew the P4M-1 between June 1950 and February 1953.
USN
Official U.S. Navy photo <a rel="nofollow" class="external text" href="http://www.history.navy.mil/our-collections/photography/numerical-list-of-images/nhhc-series/nh-series/USN-1053000/USN-1053755.html">USN 1053755</a> from the U.S. Navy <a rel="nofollow" class="external text" href="http://www.history.navy.mil">Naval History and Heritage Command</a>