"Full speed ahead, both engines!" he shouted, at the same time bidding the coxswain put the helm hard over and keep the picquet-boat dead on the buoy.
The lieutenant in the other steam-boat, having seen the nun-buoy dropped, was proceeding to another position when he, too, noticed that something was amiss, and promptly turned his craft and followed.
"Submarine foul of the bridle, sir, I think," shouted Tressidar through a megaphone.
The lieutenant had no doubt on that score, for being well astern, his steamboat was in the "wash" of the submerged craft, while the sub., being almost immediately above the submarine, was well in front of the disturbed water.
"Collar that buoy," sung out the sub., addressing the two bowmen. The latter, armed with long boathooks, poised themselves on the lurching fore-deck, like harpooners waiting for a whale to appear.
"Got her, sir," shouted one of the seamen, as he deftly engaged the head of the boathook in the metal rung of the nun-buoy. "She's carrying too much way; I can't get her aboard."
"Hold her, both of you!" exclaimed Tressidar, fearful lest the ring would carry away and the chain disappear from sight.
The picquet-boat was certainly gaining upon the submerged craft, for in a little while the seamen reported that the strain on the cable was diminishing. At length, by dint of the united efforts of the two men, the nun-buoy and about two fathoms of chain were lifted on the deck of the boat, and a couple of turns taken round the pedestal of the for'ard gun.
"Got her, by Jove!" exclaimed the sub. triumphantly as he ordered the engines to be stopped and allowed the picquet-boat to be towed by the submerged craft.
The trapped submarine had attempted to steal towards the British monitors, and having taken her bearing through her periscope, had submerged in Dutch waters. This was obvious, since the buoy, actually on the line of demarkation, had been swept away from the neutral zone.