The 1-dollar seaplane is the highest value in the Transportation Coil Series. It features a Benoist Type XIV airboat, which had been designed and built by Thomas Benoist in St. Louis, Missouri. The airboat initiated the world's first regularly scheduled airline service on January 1, 1914, with its flight between Tampa and St. Petersburg, Florida. It carried a pilot, one passenger, and a load of express cargo on the eighteen-mile flight, which took about twenty-three minutes. The stamp was issued on April 20, 1990, at the ARIPEX stamp show in Phoenix, Arizona. There were 244,775 first day covers.
The stamp was printed by the Bureau of Engraving and Printing first on the B press using plate 1 with dull gum and all over tagging and had a plate number every fifty-two stamps. In 1993 plate 3 was printed on shiny gum paper with mottled tagging using the C/D press with a plate number every forty-eight stamps. It was reprinted in 1998 on low gloss paper with solid tagging.
The 1-dollar seaplane was designed by Chuck Hodgson of Newhall, California. Gary M. Chaconas of the Bureau of Engraving and Printing engraved the vignette, and the lettering was engraved by John Masure, also of the Bureau of Engraving and Printing.