"Guess we'll stick on now," he remarked.
"Where did you get that rope?" asked Percy.
"It's all that's left of the ground-line. Thought it might come in handy, so I jammed it inside my oil-coat before I jumped. Never can tell when you'll need a few feet for something or other."
The screech of the buoy, recurring regularly, set their ears ringing.
"We've got to choke that off!" exclaimed Spurling, finally. "We'll go crazy, sure, if we have to listen to it all night."
"How'll you do it? Jam something into the mouth of the whistle?"
"Might smother it that way, but I know an easier one."
He pushed his handkerchief into the curved end of the intake tube just as the bellowing buoy reached its lowest point. The next time it sank there was no sound.
"Can't sing out unless it fills up with air," remarked Spurling. "It's human, so far!"
"Is it all right to shut the signal off altogether? Mightn't some vessel strike the shoal if she doesn't hear it?"