Lightship No. 101, now known as the Portsmouth Lightship, is one of a small number of preserved historic American lightships. Essential partners with lighthouses as aids to navigation, lightships date from 1820 when Lightship No. 1 was commissioned to mark the entrance to the Elizabeth River and the Norfolk Naval Shipyard. Built in 1916 by Pusey and Jones at Wilmington, Del., Lightship No. 101 was one of a pair of vessels and was originally known as the Cape Charles. It served on at least five stations, guiding vessels into the Chesapeake Bay, Delaware Bay, and within Nantucket Bay. The ship has undergone only minor modernization and maintains remarkable integrity for a vessel so long in service. Retired in 1964, Lightship No. 101 is now owned and operated as a historic vessel museum by the city of Portsmouth. A conspicuous landmark along the historic waterfront, this relic of navigation is a popular public attraction.