About this time, she teamed up with the decoy ship USS Charles Whittemore in hopes of luring a German U-boat to the surface.

She arrived in Bermuda on 13 November, two days after the end of World War I, and was ordered to return to the United States.

After exercises and visits in Caribbean Sea and Central American ports, L-8 crossed the Panama Canal (Burton 374) and arrived San Pedro, California, on 13 February 1919 to join the submarine flotilla on the West Coast.

Following a period of commission, in ordinary, early in 1922, L-8 departed San Pedro on 25 July for the Atlantic, arriving Hampton Roads, Virginia, on 28 September.

This was the only test with live torpedoes of magnetic exploders conducted by the Navy in the 19 years before the World War II period.