Curtis F-Boat, circa 1915 by William Ellsworth

The famous Curtiss "F" flying boat was used as a trainer for the first Coast Guard aviators. They were originally procured by the Navy beginning in 1912 and saw service through at least 1918, when they were replaced by the Curtiss "MF" flying boat. It was used for training pilots at the Curtiss Flying School in Newport News, VA.
According to a caption on a photograph in the Coast Guard Historian's files, "Second Lieutenant Norman B. Hall and 3d Lieutenant Elmer F. Stone, pioneers in Coast Guard aviation, flew in this type of Curtiss plane up and down the Virginia and North Carolina coasts to evaluate the use of aircraft to the Coast Guard. The advent of aviation in the Coast Guard was sanctioned by Act of Congress on August 29, 1916."