See main article: USS Kangaroo (SP-1284). Kangaroo was built as the private motorboat Herreshoff Hull # 316 in May 1917 by the Herreshoff Manufacturing Company at Bristol, Rhode Island, one of nine identical motor boats built in anticipation of eventual acquisition by the United States Navy from their private owners. The U.S. Navy purchased her for World War I service later that year, and she was in commission as USS Kangaroo (SP-1284) from 1917 to 1919.
USS Kangaroo had been out of commission for six months when the U.S. Navy transferred her to the United States Department of the Treasury at Key West, Florida, on 22 November 1919, for use by the U.S. Coast Guard. The Coast Guard commissioned her as USCGC Kangaroo.
The Coast Guard used Kangaroo for customs and coastal surveillance patrols. She served at Key West until assigned to Charleston, South Carolina, on 1 January 1923. She was renamed USCGC AB-6 on 6 November 1923, and later served at Norfolk, Virginia.
AB-6 was sold at Norfolk on 1 October 1932 to John H. Curtis for $200 (USD).