Lightship is a type of vessel that serves as a floating lighthouse, providing navigational aid to ships at sea. These ships are equipped with powerful lights and sound signals to mark dangerous coastlines, safe entry points, and underwater hazards. Lightships are often anchored in specific locations and can operate in areas where traditional lighthouses are impractical. Historically, lightships have played a crucial role in maritime safety since the 18th century. They are typically manned by a small crew and can be equipped with additional technology, such as radar and communication systems, to enhance their functionality. Some famous examples of lightships include the Nantucket Lightship and the Chesapeake Lightship.