The vessel was acquired by the Navy from Leonard H. Dyer of New York City, on 2 July 1917.

Departing that district on 31 May 1918, she traveled up the Hudson River to Troy, where she entered the Erie Canal on 2 June.

Ports of call on her voyage to the Great Lakes included Utica, Baldwinsville, Rochester, and Buffalo, New York.

Atlantis conducted patrols in the waters of the Detroit section of the 9th Naval District into the summer and fall, spending much of her time patrolling the "detour passage" off Pipe Island, warning steamers to stay clear of dangerous waters in the vicinity.

She commenced her voyage to return to the 3rd Naval District on 12 November 1918, the day after the armistice was signed ending the fighting of World War I.