Even as the five boys glanced at each other with startled and wondering looks, the thumping ceased abruptly. In a short space it was resumed. Instinctively the boys gathered near the spot.
While they stood there trying to determine the cause for the strange procedure, the noise ceased. They heard a tapping at one of the portholes. Jimmie rushed across the compartment to investigate.
“Hey, fellows, come over here a minute!” he called out.
“What have you found now?” questioned Ned, obeying the request.
“Here’s this chap, and he’s making all sorts of signals!”
“That’s funny!” puzzled Ned. “Can you make out what he wants?”
“He’s making his hands go in the strangest way! I’m sure I can’t interpret such motions unless he wants us to turn around while he places a bomb or something close enough to blow us out of the water.”
“I know what he wants!” shouted Harry, who had been closely observing the stranger’s repetition of the strange motions. “He wants us to open the valve leading from that sea cock where he has been working!”
“Fine business!” scorned Jimmie. “Open up the sea cock and let the ocean come running all over our nice carpets! I guess not!”
“I’m going to try it, anyway!” declared Harry. “If a little water does come in, the pumps will take care of it before it becomes dangerous. At least, it’s well worth trying!”