Men of Mosquito Navy test out antisubmarine boats at Miami, Florida.
Title reads: "America's Mosquito Navy".
Miami, Florida, United States of America (USA).
M/S of officer inspecting row of seaman wearing leathers and goggles. They are part of special Mosquito Navy section; they pilot America's "mile-a-minute" antisubmarine craft. C/U of one of the men.
M/S of men running on board antisubmarine boat. Various shots, some aerial, of convoy of special boats passing coast. The boats are an American version of the torpedo boat, as well as being submarine wrecks. According to narrator "a substantial number of these mosquito craft" will be shipped to Britain as part of Lease and Lend Bill.