Though modern personal flotation devices (PFDs) were developed for the military, reliefs in London’s British Museum from the 9th century B.C. depict enemies of the Assyrians swimming the Euphrates River supported by inflated goat skins, which may have been the original PFDs. European naval commanders were hesitant to carry PFDs aboard, fearing they would enable desertion. However, by the 19th century, Norwegian vessels carried wood planks and cork blocks to help save sailors in the event of a shipwreck. In 1841, the U.S. Patent Office issued a patent for “Improvement in Buoyant Dresses or Life-Preservers” to New Yorker Napoleon Edouard Guerin for a double-layered jacket, waistcoat, or coat hat that could be stuffed with 18 to 20 quarts of cork, and the modern life jacket was born. Most PFDs now use air or foam to aid flotation.