Eph, after having made up his mind to turn in early, had found his sleepy fit passing.  He read for a while in the cabin, then pulled on a reefer and went up on deck.  Williamson was already in a berth, sound asleep.

“It would be a fine night if there was a moon,” Eph remarked to the marine sentry on deck.

“Yes, sir.”

The marine—­“soldier, and sailor, too”—­not being there for conversational purposes, continued his slow pacing, his rifle resting over his right shoulder.

As Eph strolled about in the limited space of the platform deck he heard a distant creaking.  It was a sound that he well knew—­the hoisting of sail.

“I wonder if the local fishermen start out at this time of the night?” Eph Somers remarked, musingly, to the sentry.

“It may be so, sir; I don’t know,” replied the marine.

Presently Eph made out the lines and the spread of canvas of a handsome knockabout sloop standing on out of the harbor.

The course being narrow, the sloop was obliged to sail rather close to the fleet.

“That’s no fisherman!” muttered Somers, watching, his hands thrust deep in his pockets.

Presently the sloop’s hull was lost to Eph’s sight beyond the gunboat.  Then the boy heard a voice from the “Hudson’s” deck roar out: 

“Look alive, you lubber!  Do you want to foul our anchor chain?”

“No, sir,” came from the sloop’s deck.  “We’ll clear you all right.”

“See that you do, then!”

Then the sloop’s hull came into view again, as the craft headed out toward the open water beyond.

“That’s the kind of a craft Jack would give a heap to be on,” thought Eph.  “Queer that he should spend all his time on gasoline peanut-roasters when he’s so fond of whistling for a breeze behind canvas.”

As the sloop neared the mouth of the little bay, and her lines became rather indistinct in the darkness, Eph Somers turned to resume his pacing of the deck.

“Hullo,” muttered the submarine boy, two or three minutes later.  “Here’s the shore boat coming on its regular trip.  I wonder if Jack and Hal are in it?  It’s about time for them to be coming on board.”

But the shore boat, instead of coming out to the submarine, lay in at the side gangway of the gunboat opposite, and Eph discovered that his two comrades were not in the boat.

“I say,” hailed Eph, “have you seen Mr. Benson and Mr. Hastings on shore!”

“No, sir,” replied the petty officer in charge.

Then one of the sailors in the boat spoke in an undertone.

“This man says, sir,” continued the petty officer, “that he saw your friends, sir, going aboard a white knockabout sloop.”

“He did, eh?” demanded the astonished Eph.  “How long ago was that?”

“Only a few minutes ago, sir,” replied the sailor.

“You’re sure you saw Mr. Benson and Mr. Hastings?”