A lightvessel, or lightship, is a ship that acts as a lighthouse. They are used in waters that are too deep or otherwise unsuitable for lighthouse construction. Although some records exist of fire beacons being placed on ships in Roman times, the first modern lightvessel was off the Nore sandbank at the mouth of the River Thames in England, placed there by its inventor Robert Hamblin in 1734. The type has become largely obsolete; lighthouses replaced some stations as the construction techniques for lighthouses advanced, while large, automated buoys replaced others.
A screw-pile lighthouse is a lighthouse which stands on piles that are screwed into sandy or muddy sea or river bottoms. The first screw-pile lighthouse to begin construction was built by the blind Irish engineer Alexander Mitchell. Construction began in 1838 at the mouth of the Thames and was known as the Maplin Sands lighthouse, and first lit in 1841. However, though its construction began later, the Wyre Light in Fleetwood, Lancashire, was the first to be lit.
The Rappahannock River is a river in eastern Virginia, in the United States, approximately 195 miles (314 km) in length. It traverses the entire northern part of the state, from the Blue Ridge Mountains in the west where it rises, across the Piedmont to the Fall Line, and onward through the coastal plain to flow into the Chesapeake Bay, south of the Potomac River.
The Nab Tower was a tower planned for anti-submarine protection in the Solent in World War I. It was sunk over the Nab rocks east of the Isle of Wight to replace a lightship after the war, and is a well-known landmark for sailors as it marks the deep-water eastern entry into the Solent.
Execution Rocks Light is a lighthouse in the middle of Long Island Sound on the border between New Rochelle and Sands Point, New York. It stands 55 feet (17 m) tall, with a white light flashing every 10 seconds. The granite tower is painted white with a brown band around the middle. It has an attached stone keeper's house which has not been inhabited since the light was automated in 1979.
Ambrose Light, often called Ambrose Tower, was the light station at the convergence of several major shipping lanes in Lower New York Bay, including Ambrose Channel, the primary passage for ships entering and departing the Port of New York and New Jersey.
The Pensacola Light is a lighthouse at Pensacola Bay, in Florida. It is the third iteration of what was originally a lightship, the Aurora Borealis, and remains an aid to navigation.
Cape Mendocino Light was a navigation light at Cape Mendocino, California. The former lighthouse was relocated to Shelter Cove near Point Delgada, California in 1998, and the historic Fresnel lens to Ferndale, California, in 1948. An automated beacon operated for a number of years but was removed in May 2013.
The Lower Cedar Point Light was a historic lighthouse in the Potomac River near its eponymous point, south of the present U.S. Route 301 bridge. It has been replaced by a skeleton tower.
Wolf Trap Light is a caisson lighthouse in the Virginia portion of the Chesapeake Bay, about seven and a half miles northeast of New Point Comfort Light. It is listed on the National Register of Historic Places.
Thimble Shoal Light is a sparkplug lighthouse in the Virginia portion of Chesapeake Bay, north of the Hampton Roads channel. The third light at this location, it is listed on the National Register of Historic Places.
Frying Pan (LV-115) is a lightvessel moored at Pier 66a in the Chelsea neighborhood of Manhattan in New York City. It served at Frying Pan Shoals, off Cape Fear in North Carolina, for over 30 years.
The York Spit Light was a lighthouse located at the mouth of the York River in the Chesapeake Bay, marking a long shoal paralleling the main channel into the river.
The Stingray Point Light was a lighthouse located at the mouth of the Rappahannock River.
Smith Point Light is a caisson lighthouse in the Virginia portion of the Chesapeake Bay at the mouth of the Potomac River. It was added to the National Register of Historic Places in 2002.
The Bowlers Rock Light was a lighthouse located in the Rappahannock River in Virginia.
Chesapeake Light is an offshore lighthouse marking the entrance to the Chesapeake Bay. The structure was first marked with a lightship in the 1930s, and was later replaced by a "Texas Tower" in 1965. The lighthouse was eventually automated and was used for supporting atmospheric measurement sites for NASA and NOAA. Due to deteriorating structural conditions, the lighthouse was deactivated in 2016. At the time it was the last remaining "Texas Tower" still in use due to obsolescence.
USC&GS Drift was a United States Coast Survey schooner built in 1876 specifically to anchor in offshore waters to undertake current measurements. She was transferred to the United States Lighthouse Board on May 20, 1893 to become the lightship Light Vessel # 97 or (LV-97) on the Bush Bluff station until retirement and sale in 1918 to become the W. J. Townsend which was scrapped in 1945.
The Racine Reef Light was a lighthouse located in Lake Michigan some two miles east of Racine, Wisconsin, marking the edge of its eponymous shallows. It was torn down in 1961 and replaced with a skeleton tower on the same foundation.
