Statement of Significance (as of designation - April 11, 1989):
Now known by her last official designation "Ambrose," NO. 87 was built (1907) to serve as the first lightship on the newly established Nantucket station, where she served to guide mariners into the nation's busiest port, New York. NO. 87 is also important in the history of radio, being the first successful shipboard radio beacon used to guide ships at long distances in poor weather.