and have a look."

"Better let me do it, Frank," said Jack.

"No; you're stronger than I am. You can hold this up better."

Jack did as his chum requested and a moment later Frank disappeared
under the wreckage, diving first to make sure that he got under.

Under the water the lad swam forward. His hand touched something that
was threshing about.

He felt sure it was the German. He rose. His head came in contact with
something, but the lad opened his eyes and saw that he was above the
surface. The imprisoned German was close beside him.

"Dive!" said Frank. "You can come out all right."

"Can't," was the reply. "My arm is caught."

Frank made a quick examination.

"I can loosen it," he said at last, "but I'll probably break the arm."

"Loosen it," said the German, quietly.

Frank took a firm hold on the arm at the elbow and gave a quick wrench.
He felt something give, and when he released his hold on the man's arm,
the latter sank suddenly.

Frank dived after him quickly. It was even as the lad feared. The
German had fainted from the pain of the arm, which Frank had broken
cleanly as he released it.

Frank dived deep and his outstretched hand encountered the German. The
lad grasped the man firmly by the collar and then struck upwards. A
moment later he succeeded in making his way to where Jack still tugged
at the balloon.

Jack lent a hand and they dragged the German from beneath the wreckage.
Then they towed him to the boat and other hands lifted him in. Frank
and Jack clambered aboard.

"Give way!" said Jack, sharply.

The boat moved toward the battleship; and even as it did so, the mass
of wreckage suddenly disappeared from sight with a loud noise.

Jack shuddered.

"Pretty close, Frank," he said quietly. "You can see what would have
happened if you had still been under there."

CHAPTER IV

ATHLETICS

"Can you fight?"

The speaker was a young British midshipman. Jack and Frank stood at the
rail, gazing off toward the distant horizon, when the young man
approached them. The lads turned quickly.

"Can you fight?" demanded the young man again. His eyes rested on Jack.

"Well," said the latter with a smile, "I can if I'm pushed to it. Who
wants to lick me now?"

The young midshipman also smiled.

"It's not that kind of a fight I'm talking about," he said. "You're new
aboard, so I'll explain."

"Do," said Jack.

"Well, there has been considerable rivalry between the men of our s