“I will report the whole thing,” Mr. MacMasters said.  “But, of course, the Department receives similar and even less assured testimony every day, of suspiciously acting persons.  The information furnished the Department has all to be sifted.  There may be nothing wrong with this man Blake.”

“If he is working at the munition factory, how comes it that he is out here on an oil-laden boat?” demanded Whistler, with what he thought was shrewdness.

“Quite so.  You boys are naval apprentices, but you were out fishing to-day,” returned Mr. MacMasters, grimly.  “There is an explanation for everything, my boy.”

They ran on for another hour, but more slowly.  They did not raise a craft of any kind, and Mr. MacMasters lost hope.

“I will put you boys ashore at Rivermouth,” he said.  “You can go home by rail.  I shall not be able to put in at Seacove again to-night.  And Rivermouth is off yonder—­within a few miles.”

Even in the fog the navigator found the harbor in question without difficulty.  Just as they would have apprehended the presence of a submarine had one been near.  There are very delicate and wonderful instruments aboard American naval vessels—­instruments that may not be described at present—­that enable the officers to apprehend the near approach of other vessels and their own nearness to the shore as well.

The S. P. 888 made her landfall correctly and slipped into Rivermouth Harbor like a ghost in the fog.  There was a quantity of small shipping in the place, and Ensign MacMasters did not want to take any chances of collision.  So he hailed a fishing smack and put the four friends from Seacove aboard of her.

“Good-bye, boys!” he said, as they went over the side into the smack.  “We shall meet in a few days.  You will get your notice by telegraph when to join the Kennebunk, and where.  I shall be relieved from the command of this shark, and we’ll have a big cruise on the superdreadnaught, I have no doubt.”

He spoke prophetically, as it was proved later.  But at this time neither Ensign MacMasters nor any of the four apprentice seamen imagined just how wonderful a cruise it would be.

As the fishing smack chugged away with her auxiliary engine toward the docks of the town, the S. P. 888 swung in a narrow circle and put out to sea so swiftly that in five minutes she was completely out of sight in the fog and almost out of sound as well.

The fishermen were curious about the boys and the business of the chaser in this locality; but the Navy boys had long since learned to say nothing that would circulate information of any moment.  “Keep your mouth closed” is an inflexible rule of the Navy; the yarns Ikey told his “papa” and his “mama” notwithstanding!

As they drifted in toward shore slowly, weaving their way among the moored craft, Whistler suddenly began to sniff the air and show excitement.

“What’s the matter?” demanded Torry, his closest chum.  “You act like a hound dog on a hot scent.”