“Fred surely is a plucky old scout and a quick thinker too,” agreed Bill. “He had his shoes off and was in the water before the rest of us fairly realized what had happened.”

“He can swim like a fish,” said Teddy, “and with 16 that rope in his hand, I didn’t fear but we could get him on board again. But my heart was in my mouth when I thought of that shark.”

“It was taking a big risk,” declared Bill. “By the way, I don’t see anything more of that ugly fin. I guess he’s given us the go-by for to-day.”

But even as he spoke, there was a rush in the water alongside, and they caught a glimpse of a dark body at least sixteen feet in length, and saw a wicked eye gleaming up at them. It was only for a second and again the shark vanished. But his sudden appearance, at the very moment they were talking of him, made the boys shudder.

“He’s following us!” exclaimed Bill.

“That’s what,” said Teddy. “He knows we’re in a small boat and that the storm may capsize it. If it were a canoe or a rowboat, he’d probably try to upset it himself.”

“He couldn’t have been far off when Fred was in the water,” shivered Bill. “He may have been making for him at the very minute we hauled him out.”

“We got both out just in the nick of time, I guess,” assented Teddy soberly, and his heart was full of thankfulness as he gazed at his elder brother.

The latter just at present had his hands full. The storm had increased in fury and was now blowing half a gale. The sail threatened to split into ribbons, and the gunwale was constantly under 17 water as the Ariel plunged along. Lester’s muscles were strained to the utmost to hold the rudder against the heavy waves that seemed bound to disable it.

His face was set and worried, as he glanced alternately at sea and sky. He seemed to be debating a question that bothered him. At last he reached a decision.