On 3rd July 1942 there was made a first flight of an American flying boat Martin XPB2M Mars. It was the biggest aircraft of this kind at the time. The construction made it impossible to use those aircrafts as surveillance bombers, it was decided to use them for transportation purposes. Althogh it was a very successful aircraft, there were produced only 6 of them. The flying boats were damaged at the end of the 50s, and in 1959 the last four of them were withdrew form service by the American navy. The flying boats were bought by Flying Tankers Inc. From British Columbia and adjusted to put out fires.