"It sounds like the first move in a game to mix us up," muttered Tom Halstead, shrewdly.

"But what craft can be off at starboard?" questioned young Dawson.

"Probably a steam launch, put off from the 'Victor,' with a similar fog-horn," rejoined Captain Halstead.

"Or a motor launch," suggested Joe.

"No; I don't believe that. If it were a motor launch we'd hear the chug-chug of her exhaust. It must be a steam launch. A steam craft of small size can be run more quietly."

"That's true," assented young Dawson. "Still, our power tender has a pretty silent exhaust."

"Great scheme!" grinned Tom, suddenly.

"What?"

"I'm going to play a return trick on Rollings's captain."

"How?"