From: Dictionary of American Naval Fighting Ships, Vol.IV- p184
The first Mackinac retained her Coast Guard name. The second was named for an island in northern Michigan in the Straits of Mackinac, the word "mackinac" being derived from the Ojibwa Indian word mickilmackinac meaning "island of the great turtle."
Mackinac, a Coast Guard patrol boat, was launched at Baltimore 11 October 1902 ; accepted 1 August 1903 ; and commissioned 16 August 1903. Taken over by the Navy in 1917, Mackinac served in the 3d Naval District during World War I, patrolling the Atlantic coast. Mackinac was stricken from the Naval Register and returned to the Coast Guard 28 August 1919.