It seemed to him that she had probably been lurking in wait for the battleships that had just passed. If so, she had certainly missed her chance of doing them any damage. One of her officers climbed out to the conning-tower platform, looked searchingly around the sea, but quickly disappeared again, and the submarine dived, having paid no attention to the trawlers.
Mark, taking counsel with the skipper, went into the wireless operating-room and sent out a message, reporting what he had seen and giving the position. He did not expect his message to be picked up; but within an hour a British light cruiser came racing down from the north at twenty-five knot speed. The skipper and Mark watched her through their binoculars as she drew nearer, and identified her as H.M.S. Carlisle. They saw her suddenly alter her course, as though to avoid the mine-sweepers and possible floating mines.
"Her needn't be afeared," said Snowling. "Thar aren't no mines here now. Suppose you signals her, bor, and tells her it's all right!"
"Hold hard!" cried Mark. "Look! Look what she's after!"
In direct advance of the cruiser, he distinguished for a moment the two periscopes of the enemy submarine making a ripple as they moved through the calm water. In that same moment there was a gush of fire and smoke from one of the warship's 6-inch guns. A fountain of spray rose high into the sunlit air from where the shell had fallen. One of the periscopes seemed to have been struck. The submarine, evidently crippled, was emptying her ballast tanks to rise to the surface when a second shell struck her half-submerged conning-tower, smashing it like an egg.
"That's what I calls good marksmanship," declared old Harry Snowling. And going to the flag-halyard, he dipped his white ensign in salute.
The nearest of the trawlers hastened to the spot where the shattered submarine had gone down, hoping to save some lives; but nothing was found but a slimy patch of floating oil.
The Carlisle came within speaking distance of the trawlers, standing by for about an hour, and gave information of a new mine-field sown between the Dogger Bank and the Bight of Heligoland. Ten British trawlers, it was stated, had been captured by a German cruiser—the Schwalbe—which had taken them in to Emden. Their crews had been kept prisoners, and the boats had been fitted out as mine-layers to scatter mines indiscriminately wherever ships could sail.
The mine-sweepers were supposed to work in stretches of ten days at sea and six in port; but the Dainty and her companions continued at their task a longer time, for the danger was greater than ever the Royal Navy had counted upon.
Many neutral ships and fishing craft had been blown up, a British gunboat had been sunk, another badly damaged, and it was imperative that the seas should be kept clear. But at length a relief squadron from Grimsby came out to take over the work, and the Haddisport boats were dismissed for home.