Prior to 1914, minelaying from a ship underway had received little attention in our navy, but when some early events of the great European war showed what a part mines were likely to play in the future, mining affairs were made the principal duty of Captain G. R. Marvell in the Navy Department, the conversion of two more minelayers was pushed to completion, and mine training was taken up in earnest in the fleet. The hitherto solitary mine ship _San Francisco_ was taken out of the heterogeneous group known as the Auxiliary Division of our fleet, to become the flagship of a separate organization for mining and mine sweeping, which was established on July 10, 1915, while Admiral F. F. Fletcher had the Atlantic fleet. In the development of this new branch, which was under my command until September, 1917, one truth came out forcibly, that the sustained attention requisite throughout mining operations could only be insured by keeping everything up in man-of-war style. Laying and recovering mines was messy work, and in a ship of a type long obsolete, classed as auxiliary, and using a weapon of stealth barely tolerated, to maintain such a standard was not easy. As Sir Eric Geddes, First Lord of the British Admiralty, said in a speech in New York, “Before the war, minelaying was considered unpleasant work for a naval man, an occupation like that of rat-catching, and not attractive.” Whatever aversion may have been felt quickly vanished in the growing interest that had been aroused. Besides its own specialty, the new branch joined the fleet’s tactical, gunnery, and strategic exercises, these last leading to new activities and to study of the possibilities of mines and of the logical functions of the Mine Force. Both Admiral Fletcher and his successor, Admiral H. T. Mayo, did all in their power to establish the new element firmly as a regular part of the mobile fleet. Their interest and encouragement had immediate effect in confirming the personnel’s sense of value, which had been engendered by the variety of their employment, the stimulating results of their efforts, and belief in the power of their weapon. Experimenting with submarine nets was also taken up, and in our first six months of war, the Mine Force was employed chiefly in planting three nets in Chesapeake Bay, and one each in Long Island Sound and at Newport entrance. Success with the Long Island net, over five miles long, was only achieved after a hard struggle with a five-knot current, which time after time swept the net away or, crushing its buoys, pulled it under and entwined it with tons of kelp.