The first USS Mauna Loa (SP-28) was an armed motorboat that served in the United States Navy as a patrol vessel from 1917 to 1918. Mauna Loa was built in 1916 by George Lawley and Sons at Neponset, Massachusetts, as a private motorboat of the same name. The U.S. Navy acquired her from her owner, A. C. James, on a free lease contract on 10 May 1917 for World War I service. She was commissioned as USS Mauna Loa (SP-28) on 11 May 1917. Mauna Loa was assigned to the 1st Naval District. She patrolled the coast of northern New England until the end of the war.