The blow took the Rockpoint bully behind the ear, and Crosby let out a wild yell of pain, broken by a gasp for air, as he went under the bosom of the ocean.

As he went down, our hero gave him an extra shove and then swam with all speed for the row-boat, which had drifted several yards away.

He saw Harry and Si Peters standing up in the boat. Peters had just struck at his chum, and Harry had partly dodged the vicious blow.

But the broken oar landed on Harry’s arm, causing him to cry out from pain.

“Drop that, Si Peters.”

The command, coming so unexpectedly, startled Peters. He turned, to find Jerry at the gunwale directly behind him.

“Oh, Jerry, help!” cried Harry.

Si Peters gave a low yell of rage.

Again Harry sprang away, and now armed himself with an oar.

“You can’t frighten me, you fool!” shouted Peters. “Don’t you dare to put your hand on the boat!”