ten days three were more or less active in attacking coast-wise vessels. These three operated all the way from Cape Hatteras to Newfoundland, attempting by these tactics to create the impression that dozens of hostile U-boats were preying upon our commerce and threatening our shores. These submarines, however, attacked almost exclusively sailing vessels and small coastwise steamers, rarely, if ever, using torpedoes. A number of mines were laid at different points off our ports, on what the Germans believed to be the traffic routes; but the information which we had concerning them made it possible to counter successfully their efforts and, from a military point of view, the whole of the submarine operations off our coast can be dismissed as one of the minor incidents of the war, as the Secretary of the Navy described it in his Annual Report. The five submarines sunk in all approximately 110,000 tons of shipping, but the vessels were, for the most part, small and of no great military importance. The only real victory was the destruction of the cruiser San Diego, which was sunk by a mine which had been laid by the U-156 off Fire Island.
