Ted had joined Jack forward, carrying a coil of rope, and they were scanning the sea, when their attention was diverted by the gesticulations of Bill Witt standing well forward.  He was pointing off to port.

“Look—–­a floating mine!” he shouted.  Almost at the same moment Jack spied another mine closer up off the starboard quarter.

In a mine field!  The retreating German warships had strewn the sea with the deadly implements of naval warfare, and the Dewey had come up almost on top of a number of the unanchored explosives!

CHAPTER VIII

A RESCUE

“If one of them pill boxes bumps us on the water line it’s all day with your Uncle Sam’s U-boat Dewey,” vouchsafed Bill Witt as he stood surveying the mine field into which they had stumbled.

In response to the warning from the lookout forward, Lieutenant McClure had stopped the submarine and was taking account of the dangers that beset his ship.  The sea was running high and it was hard to discern the mines except when they were carried up on the swell of the waves.

Swept along thus with the rise and fall of water, one of the floating missiles seemed now bearing down upon the Dewey’s port bow.  Lieutenant McClure saw it just as a huge wave picked up the whirling bomb and carried it closer up toward the submarine.

“All hands below; ready to submerge!” he called out sharply, at the same time directing Executive Officer Cleary to get the Dewey under way.

“Stay here with me a moment,” continued McClure, addressing Jack.  They were standing alone on the forward deck.

Another wave brought the mine dangerously close.

“You armed?” called out Lieutenant McClure.

“Yes, sir,” replied Jack, as he drew his heavy navy automatic.

“Shoot at that mine, boy,” commanded the officer.  At the same time the young lieutenant drew his own weapon and began blazing away.  He hoped thus to explode the deadly thing before it was hurled against the Dewey.

Jack followed suit.  The target, however, was so buffeted about by the waves that it was next to impossible to sight on it.  The only thing to do was to fire at random, hoping against hope that a lucky shot would result in the detonation of the mine.

“It’s no use,” shouted McClure above the crack of the firearms and the roar of the sea.

Their shots were rattling harmlessly off the metallic sides of the mine.

By now Cleary had swung the Dewey around until she was pointed almost directly at the nearest mine, it being slightly off the port quarter.  The engines had been reversed and started, and the submarine was drawing away.

“We ought to clear this one and then be able to dive and get out of here,” said McClure.

But as he spoke a huge wave lifted the mine again and flung it full in the path of the submarine.  As though drawn by some mysterious magnet the floating explosive seemed following the Dewey at every turn—–­an unrelenting nemesis bent on the destruction of the American vessel.