“Yes, sir,” assented the midshipman, simply.

Eph turned on the current to the search-light, swinging the ray about the bay.  Then, too impatient to sit in the conning tower, the submarine boy took his place by the deck wheel.

“Will your seamen cast loose from the moorings?” Somers asked.

“Yes, sir,” replied the midshipman.

“If there’s anything wrong, good luck to you,” sounded the cool voice of Lieutenant Commander Mayhew, from the gunboat’s rail.

“Thank you, sir.”

No sooner had the moorings been cast loose from than Eph sounded the slow speed ahead bell.  Within sixty seconds the propellers of the “Farnum” were doing a ten-knot stunt, which was soon increased to fourteen.

One of the seamen now stood, by to swing the searchlight under Eph’s orders.

By the time that the submarine reached the mouth of the bay the light faintly picked up a spread of white sail, off to the East.

“That’s the knockabout,” cried Eph, excitedly.  “Now, see here, keep that ray right across the boat as soon as we get half a mile nearer.”

“It’ll show the boat that you’re chasing ’em, sir,” advised the midshipman.

“I know it,” admitted Eph.  “But it will also keep the rascals from dumping my friends overboard without our catching ’em at it.”

“What do you think the men in charge of that boat are, sir—­pirates?”

“They’re mighty close to it, if they’ve shanghaied Mr. Benson and Mr. Hastings and put to sea with ’em,” rejoined Eph.  Then he rang for more speed.  Down below, Williamson almost instantly responded.  The “Farnum” now fairly leaped through the water.

“Turn the light on the knockabout, now, and keep it there,” directed the submarine boy.

There was a seven-knot breeze blowing.  At the speed at which the submarine boat was traveling the distance was soon covered.

And now the searchlight revealed two men in the standing-room of the sloop, one of whom, a bearded man, was looking backward over his wake much of the time.

“Can one of the marines fire a shot to stop those fellows?” asked Eph Somers.

“In the air do you mean, sir?” asked the midshipman.  “Certainly.”

“Then I wish he’d do it.”

Bang!  The discharge of the rifle sounded sharply on the night air.

“It ain’t stopping ’em any,” muttered Eph, after a few seconds had gone by.

“Nothing would, unless fired into them,” volunteered Midshipman Terrell.

It did not take long, however, to run the submarine up alongside of the sloop, at a distance of about one hundred yards.

“Now, we want you men to stop,” called Midshipman Terrell, between his hands.  “We are United States naval forces, from the gunboat, and you will regard this as an order that you must obey.  No!” thundered the midshipman, suddenly, as the bearded one started to step down into the cabin.  “You will both keep on deck.  Otherwise we shall be obliged to fire into you.  We mean business, remember!”