This was done and the U-6 did not come to the surface again until her commander felt sure that he had no longer need to fear the single remaining German battleship.  Then, upon the surface again, Lord Hastings, Frank and Jack ascended the bridge.

Through their glasses, far back, they could still see the German battleships, which, though wounded unto death, were still afloat, apparently battling desperately to resist the sea that was trying to draw them under.  The water was still full of bobbing heads—­the German sailors who had leaped into the sea.

“Poor fellows,” said Lord Hastings compassionately.

“Why didn’t the other ship stop and pick them up?” demanded Jack.

“Didn’t have time, I guess,” returned Jack dryly.  “Her commander was in too big a hurry to get away from there.  He deserves the same fate for running away from them, if you ask me.”

“He certainly does,” agreed Lord Hastings.  “However, there is nothing we can do for the poor sailors in the water; we have no room for them here.  They will have to shift for themselves.  It’s the fortune of war.”

“And now where to, sir?” asked Frank.

Lord Hastings looked at him amusedly.

“I guess that is the hundredth time you have asked me that question,” he said.  “However, I don’t mind answering it, although you will find some day, should you chance to serve under another commander, that such questions are not received with very good grace.  I believe we shall take another little run into Ostend.”

“Good, sir!” said Jack.  “We did very well on our last trip.  Perhaps we shall be fortunate enough to learn something this time.”

“Who knows?” said Frank, with a shrug of his shoulders.  “However, the nearer the enemy we are, the more chance for action.  The sooner we get started the better I shall be pleased.”

“It’s a short run from here,” said Lord Hastings, “and I believe we shall be safe enough if we make the attempt in broad daylight.  We’ll take a chance.”

He gave the command to go forward and the U-6 moved swiftly ahead.

As Lord Hastings had said, it was not a long run, and two hours later, standing on the bridge, the boys made out in the distance the lofty spires and steeples that they felt sure was the Belgian seaport.  And they were right.

The U-6 was not molested, not even challenged, as she moved slowly into port, flying the German flag, her officers and crew all attired in German uniforms.

“Where are all the big German battleships?” asked Frank in surprise, after sweeping his eye over the water in all directions in a vain effort to locate one of them.

Jack smiled.

“You ought to know there are no German battleships here,” he said.

“But——­” began Frank.

“The battleships are still safely bottled up in Heligoland,” Jack explained.  “While Ostend is called a German naval base, it is, strictly speaking, nothing but a submarine base.  The under-sea boats have been able to run in here without much difficulty, but the larger vessels could hardly get by on the surface.”