Alpha, a motor yacht, was built in 1911 at Riverside, Rhode Island, by the Narragansett Bay Yacht Yard. She was purchased by the Navy on 19 May 1917 from Joel Fischer and commissioned that same day. Assigned to the 2d Naval District section patrol, Alpha patrolled the waters of southern Massachusetts, Rhode Island, and Connecticut. The motorboat served the Navy through the end of World War I and into 1919. On 23 December 1918, Alpha suffered a fire while at Melville, Rhode Island. The Navy tug Mariner steamed from Newport to assist Alpha and her crew.