Jack was right.  The harbors of Ostend and Zeebrugge had been effectually sealed.  No longer would enemy U-Boats make nightly raids into the North Sea, only to scurry back to their bases when it grew light.  As a submarine base, Zeebrugge was extinct.  So, for that matter, was Ostend.

That the success of the British expedition had been a severe blow to the Germans goes without saying.  No other single feat since the beginning of the war had done so much to dishearten them; and there is little doubt that the sealing of their submarine bases did much toward hastening the end of the war.

British losses in the raid had been severe.  The Vindictive, which had led the attack, had literally been shot to pieces and it was a miracle how she remained afloat.  The Brigadier, also, had suffered severely, but her condition was not so bad that a few months in drydock would not be sufficient to make her whole again.

A dozen or more of the little motorboats and coastal patrol vessels had been sunk, and the loss of life had been heavy.  Several others of the destroyers had been badly damaged, but there was not one of the larger vessels sunk or crippled so badly that she could not return to her home port.

It still lacked an hour of daylight when the allied fleet drew off, its work accomplished; and behind in the ports now sealed, the anger of the Germans flared forth anew.

The damaged British ships were immediately put into drydock in British ports, and Jack and Frank at once returned to Dover to report to Lord Hastings.  The latter greeted the lads with outstretched hands.

“It was a gallant exploit,” he exclaimed, “and I am sure both you boys had important roles to play.”

“I guess we did, sir,” Frank admitted.  “At the same time, I’m glad to be safely back here again.”

“I suppose, sir,” said Jack, “now that the enemy submarines caught outside are without bases, there is little fear of their attempting the trans-Atlantic trip?”

“On the contrary,” said Lord Hastings, “they are more likely than ever to do so.”

“But they must have a base, sir,” protested Frank.

“Not necessarily,” smiled Lord Hastings.

“Then how will they replenish their supplies of food and fuel?”

“Well,” said Lord Hastings, “if they can snare a victim every three or four days it should be enough.  From a merchant ship they can get all the food and fuel they need before sinking her.”

“That’s so, by George!” Frank exclaimed.

“It stands to reason,” said Lord Hastings, “that those submarines which were not bottled up in the harbors have been warned not to return.  Now, it wouldn’t surprise me a bit if they headed directly for America.”

Jack grew thoughtful.

“It’s too bad,” he said at last, “that the Brigadier was so crippled that we cannot resume our interrupted voyage.”

Lord Hastings smiled.