Raising one arm he waved to those on deck, then releasing his hold he allowed himself to drop into the deep. The "Ramillies" was anchored in nine fathoms, but ere the sub reached bottom nearly a hundred and twenty feet of life-line and air-tube were paid out. With an effort he gained his footing and commenced to walk in the direction of the ship’s anchor, battling against the two-knot current that swirled past him. Although the sun was shining brightly and the light at that depth ought to be fairly strong, the sand and mud churned up by the tidal current made it impossible to see beyond a few yards. With nothing to guide him, for the life-line was quivering in the swirling water, Hythe struggled stolidly in the supposed direction. He realized that he was practically on a fool’s errand. The mysterious person or agency who had been responsible for attaching the message to the anchors of the squadron was not likely to remain upon the scene of his exploit, while already all the sought-for traces must have been obliterated by the tide. Presently two eerie-looking shapes ambled towards him. They were his companions, Banks and Moy. "Well, if I am going in the wrong direction, those fellows are making the same mistake," thought the sub. "So here goes." Another thirty yards were laboriously covered. Here and there the divers had to make a detour to avoid the wavy trailing masses of seaweed, that, if not actually dangerous, would seriously impede their progress, while at every few steps numbers of flatfish, barely discernible from the sand and mud in which they were partially buried, would dart off with the utmost rapidity. "Thank goodness, here’s the shot-line," exclaimed the sub, as a thin rope, magnified under water to the size of a man’s wrist, became visible in the semi-gloom. The shot-line, terminating in a heavy piece of lead, had previously been lowered to serve as a guide for the divers to work from. Pointing in two opposite directions Hythe signed to the two men to begin their investigations, while he, taking a route that lay at right angles to the others’ course, began once more to struggle against the current. Ere he had traversed another ten yards his feet slipped into a slight depression. It was the hole scooped out by the flukes of the "Ramillies’" stockless anchor. "Could do with a lamp," he remarked to himself, then stooping he began to examine the bed of mud and sand in which he stood. Beyond the almost filled-in cavity and the faint traces of the sweep of the battleship’s anchor-chain there was nothing to attract his attention. He turned to look at his own footprints. They were already practically obliterated, so it was hopeless to expect to find the footprints of the mysterious diver or divers who had contrived to visit each of the anchors of the battleships in turn. "Anything to report?" asked a voice through the telephone. "No, sir," replied the sub.