Now in this densely packed shipping area [declared Admiral Sims], extending, say, from the north of Ireland to Brest, there were seldom more than eight or ten submarines operating at any one time. The largest number I had record of was fifteen, but this was exceptional. The usual number was four, six, eight, or perhaps ten. We estimated that the convoys and troop-ships brought in reports of sighting about three hundred submarines for every submarine actually in the field. We also estimated that for every hundred submarines the Germans possessed, they could keep only ten or a dozen at work in the open sea. Could Germany have kept, let us say, fifty submarines constantly at work on the great shipping routes in the winter and spring of 1917, before we had learned how to handle the situation, nothing could have prevented her from winning the war. Instead of sinking 850,000 tons in a single month, she would have sunk 2,000,000 or 3,000,000 tons. With such handicaps it was all the more creditable to the _Corsair_ and her sister yachts that they were able to accomplish so much in the summer of 1917, before they were shifted to the troop and supply convoys. It was knight-errantry, in a way, this work of the Breton Patrol—rough-riders of the sea whose spirit was akin to that of the impetuous regiment which Theodore Roosevelt led at Santiago. The Breton pilots were eloquent in admiration, but shrugged their shoulders at the notion of weathering a Bay of Biscay winter in these yachts, so slender, so elegant, of such light construction, of a certainty built for pleasure and _le sport_! The programme of patrol duty sent the larger yachts out two and two, each pair to be relieved after four days at sea. The _Corsair_ and _Aphrodite_ were coupled as cruising in adjoining areas, and when they returned to port the _Noma_ and _Kanawha_ went out to take the same stations. The smaller yachts of the “Suicide Fleet” were assigned areas nearer the Breton coast, where they guarded the shipping that flowed alongshore between the Channel and the ports of France and Spain. The Patrol Instructions included the following plan of operation: When on an area patrol, vessels shall steer courses to cover the area but the method adopted must be irregular. Do not proceed with such regularity that the vessel’s position may be plotted. When on a line patrol, vessels shall proceed along the line of patrol until reaching its extremity when a return over the same line will be made. The courses steered must be such that the advance of the vessel will be along the _base course_. When on patrol, vessels shall speak all ships sighted. Obtain the following information: (a) Name of vessel (b) From where bound (c) To where bound (d) Character of cargo (e) Nationality (f) If defensively armed or not (g) If escort is desired