USS Koka (AT-31) was a Bagaduce-class fleet tug in the service of the United States Navy.

She was launched 11 July 1919 by the Puget Sound Naval Shipyard, and commissioned 18 February 1920.

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.

[2] On 7 December 1937 Koka ran aground off San Clemente Island and was officially decommissioned the same day.

The wreck of the Koka lies in 10 feet (3.0 m) of water in Northwest Harbor, San Clemente Island.