“What’s the matter?” called Jimmie from his position.
“I don’t know!” declared Harry. “It sounded as if that fellow had tied a can to us and we’d set it going! What did he do?”
“Let’s pump the ballast out and rise straight to the surface,” suggested Ned. “I noticed that he did that. Maybe there’s a reason!”
Harry lost no time in acting on this suggestion. The electric pumps were not long in emptying the ballast tanks. With this weight removed, the boat quickly shot upward to the surface.
As the conning tower portholes rose above the surface, the boys noticed that the afternoon was far spent. Darkness already was gathering.
Ned was working frantically at the clamps securing the hatch cover. With a cry of delight he swung the cover out of position, admitting a cool breeze. The wind had died down, leaving the surface of the ocean comparatively smooth. Sufficient breeze was moving, however, to serve the purpose of airing out the interior of the craft without putting the great fans into commission. All the boys came to the tiny deck.
Lying but a few fathoms from their port side they discerned the other submarine. Clearly distinguishable on the sides were the great letters “U-13” painted in almost exact duplicate of those on their own boat.
“What do you know about that?” was Jimmie’s surprised exclamation. “If that fellow isn’t a dead ringer for this ship, I’m a Dutchman!”
“He surely does look a whole lot like us!” agreed Ned.
“I say, Frank,” put in Harry eagerly, “is that the fellow that sank the ship you were on? Can you identify it now?”