(Str.: dp. 7,620; 1. 379' 9", b. 48' 3", dr. 22' 6"; s. 14.5 kts.; cpl. 493; a. 1 5", 2 3", 2 mg.)

The third Roanoke (Id. 1695), a minelayer, was built in 1901 as the steel-hulled steamer El Dia at Newport News Shipbuilding & Dry Dock Co., Newport News, Va., and operated by the Southern Pacific-Morgan Steamship Co. on its New York-New Orleans-Galveston route until 1917. El Dia was one of eight former merchant vessels converted into mine planters for Capt. Reginald R. Belknap's Mine Squadron 1, Mine Force of the Atlantic Fleet. She was the first of four Morgan liners acquired, the others were Housatonic, Canonicus, and Canadaigua. El Dia was delivered to the Navy on 16 November 1917 at Tietjan and Lang's Shipyard, Hoboken, N.J., where work on her conversion promptly commenced. She was commissioned as Roanoke on 25 January 1918, Capt. Clark D. Stearns in command, and following several days of electrical work at the Brooklyn Navy Yard, she dropped down to Gravesend Bay for mine training. Roanoke then stood out to sea for a week of independent shakedown, general cleanup, and preliminary shipboard drills, finishing up the cruise at Hampton Roads, Va., on 12 April. Upon arrival, she received her complement of mines from the mine carrier Lake Superior and from Southern Railroad Pier No. 4 at Pinners Point, Portsmouth, Va. Roanoke then steamed for Newport, R.I. took on 250 men destined for the mine bases in Scotland, and sailed on 3 May via New York for the Clyde. She arrived at Base 17, Invergordon, Scotland, on 18 May. Through the end of the war, the ships of Mine Squadron 1 operated out of Inverness and Invergordon, planting the mines of the North Sea barrage. Roanoke's part in this precise demanding task ended with her return to the United States early in 1919. Following alterations at the Navy Yard, Portsmouth, N.H., she was assigned to the Cruiser and Transport Force on 10 March 1919. In this capacity, she made four voyages between the east coast of the United States and France, returning 5,500 troops home. Roanoke decommissioned on 30 August 1919 and was transferred to the War Shipping Board for return to her owner.