Another half-hour passed, but the skipper still remained out of sight. The wind had now dropped, and the smack, with her main-sheet slacked right off, floundered heavily, dipping her boom-end at every roll. Already the day was breaking beyond the chalk cliffs of the Isle of Wight. Momentarily, the search-lights from The Needles Channel batteries were growing fainter in the grey dawn.

"Isn't it grand!" exclaimed Leslie, inspired by the sight of daybreak at sea.

The sub merely shrugged his shoulders. Untold spells of duty as officer of the watch had made him regard the spectacle with complete indifference.

But the next instant Jack Sefton's lassitude fell from him like a discarded mask, for, at less than a hundred yards on the Fidelity's port quarter, appeared the pole-like periscopes of a submarine.

[CHAPTER XX--Captured]

For a few seconds the optics of the submerged craft remained trained upon the isolated smack. Although the submarine was forging slowly ahead, the periscopes rose no higher out of the water. Evidently those in charge of the vessel were not anxious to rise to the surface until they had satisfied themselves that it was fairly safe to do so.

His attention attracted by his brother's fixed gaze, Leslie sprang to his feet and grasped the weather shrouds.

"What's that, Jack?" he asked.

"What you wanted to see--a submarine."

"One of ours?"