Lightships are floating lighthouses anchored in coastal waters to mark dangerous areas, such as reefs or shipping lanes. They are equipped with powerful lights and sound signals to guide ships safely, especially in foggy conditions. Lightships serve as a vital navigational aid for mariners, ensuring safe passage through treacherous waters. Typically, lightships are manned by a small crew who maintain the equipment and ensure the light operates continuously. Some famous lightships include the Nantucket Lightship and the Chesapeake Lightship. Over time, many lightships have been replaced by fixed lighthouses or buoys, but they remain an important part of maritime history.