At the end of a minefield, the wing and the center ships simultaneously would drop mark buoys, 250 yards from the last mines, and again one mile farther on, making in all six buoys in two lines. When we came back after 10 days or so, to continue that field, a destroyer would go well ahead, to sight and stand by the outermost buoy, and the flagship would lead for it, but not steer towards the minefield side of it until the inner line of buoys had been sighted—those which were only 250 yards from the mines. The outer buoys were regarded with suspicion until some of the inner ones were seen to be in place. It was then deemed safe to lead between the two lines of buoys, for as long as there were any between the ships and the minefield, ships would be at least 250 yards clear. Passing in column midway between the lines of buoys to make the start, and allowing for the simultaneous turn into line abreast, the squadron could begin mining by the time the outer buoys were passed, thus leaving a gap of but little more than a mile between the mines in the old field and those in its continuation. An early care while fitting out had been to organize and train a good lookout service. This duty is a severe tax on the men, and when, time after time, they see nothing suspicious, they tend to relax. Fearing this, as we had yet seen no submarines, barring an alarm on the first excursion, a special warning to lookouts was issued, which, fortunately was well supported on our next trip. A beautiful, peaceful evening off the Orkneys was rudely interrupted by messages from three different sources within the space of a minute, reporting a submarine estimated to be a half-hour ahead of us, outbound, making for Fair Island Channel. Taking no chances on its having innocent intentions towards us, Captain Godfrey turned his flank destroyers outward and bang! bang! went four depth charges, and four more on the other side—just to let the sub know he might except a hearty reception. The _Aroostook’s_ siren then shrieked for “torpedo to starboard!” the ship charging ahead across another’s bows, and the _Housatonic’s_ steering chain took that occasion to break. Serenity was gone, for a time at least, but being in a swept channel, there was small choice for maneuvering. All we could do was to shorten up our formation before dark shut in and trust to our escort and a good lookout. In the event of a submarine appearing, our rôle was to make off, leaving the attack to the destroyers and being careful not to harm them by our own fire. The escort was prepared to engage its own kind, as well as submarines, and even to make a sacrifice attack on light cruisers, to assist our escape under cover of a smoke screen, but our moderate speed—15 knots at best when keeping together—and the small number and caliber of our guns, made us rather helpless against an enemy cruiser’s long-range, 6-inch gunfire and high speed.