Assigned to the 11th Naval District, Koka sailed from Puget Sound to San Diego, California in March 1920, and spent the next 17 years performing various tug and target-towing services out of San Diego. One of its yearly duties, shared alternately with Navy Eagle boat 34 as related by Max Miller in his 1932 book I Cover The Waterfront, including taking a team to Guadalupe Island off Mexico to capture elephant seals for the San Diego Zoo.[1] On 20 March 1934 she had the honor of towing out of San Diego on the homeward leg of Constitutions 1930s tour of the United States.[2]
On 7 December 1937 Koka ran aground off San Clemente Island and was officially decommissioned the same day. She was declared unsalvageable and abandoned as a wreck on 22 January 1938. Her name was struck from the Naval Register on 2 March 1938. The wreck of the Koka lies in 10feet of water in Northwest Harbor, San Clemente Island.