They had been watching the preparations made by some of the battleships to meet the constant danger from a submarine, for of late it had been rumored that the Germans had succeeded in shipping an undersea boat in sections through Bulgaria, and that it might be heard from any day.
Since that time one of the larger submersibles is said to have made the long water trip past Gibraltar, and the entire length of the Mediterranean, arriving unexpectedly in time to do terrible damage among the Allied fleets; but earlier in the summer even the threat of hidden peril gave the commander of the flotilla grave concern.
In some cases nets were used to protect a vessel lying to or drifting; but as a rule their greatest protection lay in an utter absence of lights aboard. Like grim shadows the floating batteries lay here and there on the sea, ready with steam up to move at any time. The destroyers hovered near by, constantly on guard; and from time to time brilliant searchlights would sweep the surroundings so thoroughly that not even a rowboat could escape their penetrating ray.
It can be easily understood that these arrangements so deeply interested the two boys that they could not bear to leave the deck until told by a steward that supper was waiting in the mess-room. That appealed strongly to Amos, whose appetite, always fair, had been considerably sharpened by the salt sea air.
The officers whom they met at supper were a very kindly set. They had heard enough about the American lads to feel considerable interest in their fortunes. Besides, being men who knew what it was to take chances, they could admire pluck no matter where found.
The daring feat of Jack and his chum in capturing the notorious blockade runner, Captain Zenos, and his entire crew, without any outside assistance, made the boys heroes in the eyes of the British officers. Hence they paid them constant attention, and stood ready to extend a helping hand whenever asked.
Jack, always looking ahead, asked many questions as he ate his supper. In this way he managed to pick up much information concerning things that bore an intimate connection with the enterprise he and Amos had in view.
He had explained to him how those dangerous night landings were effected, so as to take as few chances as possible. One of the officers had been ashore, it happened, and was able to tell something concerning the nature of the rough ground likely to be encountered, cut up in large and small gullies that would make any advance on the part of the troops a difficult proposition indeed.
Later on the boys once more sought their favorite place on deck to spend some time in talking matters over.
Night had now settled down over the sea, though it was hardly as dark as might be expected later on. They could make out the shadowy outlines of one or two fighters of the fleet not far away. Few sounds were heard, as silence had been impressed upon every crew; and such labor as could be left until morning was suspended.