“A submarine, for instance?” chuckled Frenchy, soon becoming pacified.  “Ikey’s father thinks maybe he might bag one while we’re out here.”

“I’d like to get a close-up view of one of those submarine chasers,” remarked Torry, finding the horn in the forward locker.  He tooted it raucously, and then continued:  “They say some of ’em can go like the wind.”

“Go right through a tub like this, if once we got in the way,” commented Whistler.  “Mind you! faster than the Colodia—­and that’s some speed.”

“Wow!” cried Frenchy.  “Don’t believe anything on water ever does go faster than a torpedo boat destroyer.”

“Oh, yes, there are faster boats.  How about a hydro?” Phil said, when Ikey broke in with an inquiry: 

“Say! lemme ask you:  Why do they call the Colodia and her sister ships ‘torpedo boat destroyers’?  We don’t see many torpedo boats anyway.  They are all old stuff.”

“That’s right,” Torry said.  “What is the why-for?  All naval craft are supposed to be destroyers anyway—­I mean service craft.”

Morgan was the oracle on this occasion.

“Ikey is right.  I’ve read that torpedo boats antedate the Spanish War.  Their exclusive business was to run up close to an enemy battleship and deliver against it an automobile torpedo.  These boats were great stuff in the beginning.

“Then they invented a craft as an antidote for the torpedo boat—­the torpedo boat destroyer.  Our Admiral Sims called this new vessel ’a tin box built around a mighty big engine.’”

“Wow!  And he is right,” cried Frenchy Donahue.  “That’s just what our Colodia is.”

“And these subchasers are still faster,” Torry observed.  “They tell me they can make thirty-five, and better, an hour.”

“Oi, oi!” cried Ikey Rosenmeyer at this juncture.  “Speak of the Old Harry and hear his wings, yet!  What’s that off yonder?”

The Sue Bridger was now skimming out of the cove, and the fog was lifting.  They got a sight of a patch of open sea across which a low, gray vessel was shooting like a shark after its prey.

“What a beaut!” shouted Torry.

“That’s one of the new chasers all right,” Whistler agreed.  “Their base is at New London where the submarine base is.”

At that moment the sun broke through the murk overhead.  Its rays shone brilliantly upon the patch of blue sea on which the submarine patrol boat steamed at such a rapid pace.

The sunbeams pricked out the letters and figures painted so big upon the side of the craft and the Navy boys repeated in chorus: 

“S.  P., Eighty-eighty-eight.”

CHAPTER V

THE STREAK ON THE WATER

The Navy boys arrived at the patch of shallow water over the Blue Reef at about noon.  By that time the fog was pretty well dissipated, and they had a clear view of miles and miles of sea as well as of the coastline behind them and the narrow entrance to the cove.