On 10 April 1919, she suffered damage in a collision with an unnamed Panama Railroad Company tug, and she underwent repairs at Port Richmond, Staten Island.

Proceeding via Boston, Massachusetts, she arrived at Kirkwall, Scotland, on 5 June 1919 to begin her tour of duty with the United States Minesweeping Detachment, North Sea.

Along with U.S. Navy submarine chasers, chartered British naval trawlers, and fellow Lapwing-class minesweepers, Flamingo participated in the clearing of the North Sea Mine Barrage.

Laid by the U.S. Navy after the United States entered World War I, the barrier had served as a formidable obstacle for German submarines based at North Sea ports.

On 23 June 1919, Flamingo transported officers and men from Kirkwall to Inverness, Scotland, and returned to her base in the evening carrying supplies for the detachment flagship, USS Black Hawk (Destroyer Tender No.

On 11 July 1919, she departed to assist in clearing Group 11 of the mine barrage in the second phase of the fourth clearance operation conducted by the Minesweeping Detachment.

The underwater blast badly damaged the rudder, disabled the capstan and generator, and dished in the ship's stern plating in several places.

Later in August, Flamingo resumed her minesweeper duties with the detachment, working out of the Norwegian ports of Lervic, Stavanger, and Haugesund before returning to Kirkwall via Otters Wick, Orkney, on 7 September 1919.

Once the arduous and dangerous job was complete, Flamingo departed Kirkwall on 1 October 1919 and, after a voyage which took her via Plymouth and Devonport, England; Brest, France; Lisbon, Portugal; the Azores; and Bermuda, eventually arrived at Tompkinsville on 20 November 1919.

It also decided to pursue the development of radio acoustic ranging, a new concept involving a method for determining a ship′s precise location at sea by detonating an explosive charge underwater near the ship, detecting the arrival of the underwater sound waves at hydrophones at remote locations, and radioing the time of arrival of the sound waves at the remote stations to the ship, allowing the ship′s crew to use triangulation to determine the ship′s position.

Under his direction, Guide both tested her new echo sounder's ability to make accurate depth soundings and conducted radio acoustic ranging experiments in cooperation with the United States Army Coast Artillery Corps.

[1] In late November 1923, with Heck aboard, Guide departed New London, Connecticut, bound for her new home port, San Diego, California, via Puerto Rico and the Panama Canal, with her route planned to take her over a wide variety of ocean depths so that she could continue to test her echo sounder.

Before she reached San Diego later in December 1923, she had accumulated much data beneficial to the study of the movement of sound waves through water and measuring their velocity under varying conditions of salinity, density, and temperature, information essential both to depth-finding and radio acoustic ranging.

[1] Under Heck's direction, Guide then conducted experiments off the coast of California during the early months of 1924 that demonstrated that accurate echo sounding was possible using the new formulas.

While the alterations were still in progress, Imperial Japanese Navy aircraft attacked Pearl Harbor, Hawaii on 7 December 1941, plunging the United States into World War II.

Between 3 and 6 July 1942, Viking assisted two U.S. Navy local patrol craft, YP-267 and YP-269, which had run aground off San Diego, towing them both back to port for repairs.

On 31 December 1944, Viking departed San Diego in company with the fleet ocean tug USS Tenino (ATF-115) bound for Clipperton Island.

She lay at the Naval Supply Depot at San Pedro until sold on 22 July 1953 to Nathan Cohen and Son, Inc., of Los Angeles, California.