USS Helianthus (SP-585)

USS Helianthus (SP-585) was a patrol vessel in commission in the United States Navy from 1917 to 1919, seeing service in World War I. After her U.S. Navy service, she was in commission in the United States Coast and Geodetic Survey as the survey launch USC&GS Helianthus from 1919 to 1939. She was named after the Helianthus, the genus to which the sunflower belongs.

Construction
Helianthus was built as a private motorboat of the same name in 1912 at Bristol, Rhode Island, by the Herreshoff Manufacturing Company.

United States Navy service, 1917–1919
The U.S. Navy acquired Helianthus from her owner, N. A. Herreshoff, on 11 June 1917 for World War I service as a patrol vessel and commissioned her on 6 July 1917 as USS Helianthus (SP-585) with Boatswain T. H. Rich in command.

Helianthus was assigned to section patrol duty in the 2nd Naval District during World War I. She operated on harbor patrol and harbor entrance patrol in Narragansett Bay and at Newport, Rhode Island.

Helianthus collided with the fishing vessel T.H.C. on 12 June 1918 off Warren, Rhode Island. The owner of T.H.C., the Warren Oyster Company, filed for $3,840.56 in damages, but was granted only $50.00 in compensation by the United States Congress.

United States Coast and Geodetic Survey service, 1919–1939
The U.S. Navy transferred Helianthus to the United States Coast and Geodetic Survey on 28 March 1919. Commissioned as USC&GS Helianthus, she served as a survey launch during her years with the Coast and Geodetic Survey, conducting hydrographic survey work primarily in the waters of the Territory of Alaska. The Survey sold her in 1939, and her subsequent fate is unknown.