The ensign of the United States is the flag of the United States when worn as an ensign (a type of maritime flag identifying nationality, usually flown from the stern of a ship or boat, or from an installation or facility of the United States Navy, United States Marine Corps, United States Coast Guard or the National Oceanographic and Atmospheric Administration ashore). International maritime law—see International Treaty on Law of the Sea, articles 91 and 92—provides that vessels have a "national character" and thus should display a flag (ensign) that corresponds to this national character, especially when in international or foreign waters. Vessels that are formally documented under the federal vessel documentation act, vessels owned by government bodies in the United States, and vessels in the U.S. military unquestionably have U.S. national character, and thus properly hoist a U.S. ensign to show their national character. Vessels that are numbered by the states (see 46 USC section 411) and small, non-registered craft owned by U.S. citizens and not registered in other countries may also hoist a U.S. ensign to show their national character. The U.S. Yacht Ensign (a variation of the national ensign; see below) is often used in place of the national flag by U.S. pleasure craft when operating within U.S. waters; this flag was legally required for licensed yachts from 1848-1980, and the practice continues among all U.S. pleasure craft in U.S. waters by longstanding historical use and custom. Additionally, a few smaller pleasure craft operated by members of the United States Power Squadrons will fly the U.S. Power Squadrons flag as an ensign in inland waters in lieu of the national flag (see below). All vessels of U.S. national character should display the national ensign when operating in international and non-U.S. waters. Military ensigns The naval ensign and its first salute The Grand Union Flag was the de facto first U.S. naval ensign. It was first raised aboard Continental Navy Commodore Esek Hopkins' flagship on the Delaware River on December 3, 1775; John Paul Jones, then the ship's senior lieutenant, personally claimed this honor. The current "Stars and Stripes" design was first adopted when the Second Continental Congress passed the Flag Resolution of June 14, 1777: "Resolved, That the flag of the thirteen United States be thirteen stripes, alternate red and white; that the union be thirteen stars, white in a blue field, representing a new constellation." Subsequent