“Someone struck him before he went overboard,” said Mark.

“You saw that?”

“Yes, sir.”

“Then he has gone. We never saw him swimming. I’m afraid we must begin to row for the ship if we do not see him in a few minutes. She’s leaving us a long way behind.”

“I see him, sir,” cried the coxswain. “Here he is!”

He made a dash with his boathook, but the object he sought to reach was so far out, that he overbalanced himself and went in with a heavy plunge.

“You clumsy dog!” roared the lieutenant. “Back water port, pull starboard. That’s it. Now then, in oars there, and lay hold of him.”

The men on the port side obeyed, and in their excitement, three started up and reached out to seize their struggling comrade, who had hold of a black arm with one hand, and swam with the other.

“Now then, lay hold quick,” roared the lieutenant.

“Mind! Take care!” shouted Mark.