Every protective measure possible was employed against them. A fleet of mine-sweepers was constantly engaged in sweeping channels and entrances to harbors, and every point where there was reason to believe mines might be laid. Fifty-nine vessels were engaged in this duty, most of them assigned to the districts which handled the largest volume of shipping. Naval vessels and the larger merchantmen carried paravanes, which swept up mines and carried them off from the vessel, where they could be destroyed. But even the paravanes were not always effective. It was one of these floating mines which sank the cruiser _San Diego_ July 19, 1918, off Fire Island. The battleship _Minnesota_ struck one of them at night, September 29th, at 3:15 a. m., twenty miles from Fenwick Island Shoals lightship. Though the explosion, under her starboard bow, seriously damaged the hull and flooded the forward compartments, the _Minnesota_ proceeded to port under her own steam, arriving at 7:45 p. m. at the Philadelphia Navy Yard, where she was docked and repaired. The British steamship _Mirlo_ was blown up off Wimble Shoal buoy, near Cape Hatteras, at 3:30 p. m., August 16th. The ship, which was loaded with gasoline, took fire, and one explosion after another occurred, breaking the vessel in two. The _San Saba_, formerly the _Colorado_, was sunk off Barnegat, October 4th. Struck amidships, the vessel practically broke in two, and sank in fire minutes. The _Chaparra_, a Cuban steamer, was blown up ten miles from Barnegat Light, October 27th. The U. S. cargo steamer _Saetia_ (Lieutenant Commander W. S. Lynch), bound for Philadelphia from France, was sunk by a mine on November 9th, two days before the armistice. The ship was ten miles southeast of Fenwick Island Shoals when an explosion occurred under No. 2 hatch, which shattered the vessel and sent it down. Besides the crew there were aboard 11 army officers and 74 soldiers. All were rescued. Enemy mines, scattered, as they were, over a thousand miles, would undoubtedly have taken a much greater toll of shipping if the Navy had not been so energetic in sweeping mines and destroying them whenever they appeared. Summarizing the entire operations of German submarines which were assigned to American waters, 79 vessels were sunk by gunfire or bombs. Of these 17 were steamers, the others being sailing vessels, most of them small schooners and motor boats. Of the 14 steamers torpedoed, but two were American, the _Ticonderoga_ and _Lucia_, both of which were sunk far out in the Atlantic, hundreds of miles from our shores. Of the seven vessels mined, one, the _Minnesota_, got to port under her own steam, and another, the tanker _Herbert L. Pratt_, was salvaged, both being repaired and put back into service. Several vessels sunk or bombed by submarine were later recovered and repaired, including the big steamer _Frederick R. Kellogg_.