The last was quite unnecessary. Dawson had already heeled the Albacore around on wingtip and was tearing full out in the direction of the strange looking object. And then, when they were still a few miles short of the spot, something else happened. Something that caused both youths to let out a simultaneous cry of wild excitement. The bow of a dull painted blue-green submarine came poking up through to the surface of the water not over a hundred yards from the bobbing wing.
In the matter of a few seconds the top half of the undersea craft was above water, and riding on an even keel. And once again Dave and Freddy saw the conning tower hatch open up, and squat little figures pop out and go scampering forward to the bow gun. It was the sight of that little bit of action that helped Freddy Farmer to find his tongue.
"That's the same boat as yesterday, Dave!" he cried. "Or an identical sister ship, anyway. Look out for the beggars. For heaven's sake don't let them shoot us down two days in a row. Better not get too close to the blighters."
Dave didn't say anything. The eyes he held fixed on the submarine were brittle with anger, and memory caused a lump of cold rage to swell up bigger and bigger inside of him. However, he made no effort to climb for altitude. As a matter of fact, he reached out his free hand and deliberately throttled the Bristol Taurus down to a whisper. Freddy reached forward and rapped him sharply on the shoulder.
"You in your right mind, Dave?" he cried. "What in the world's the idea? You're making us a perfect target for them. Have you gone balmy?"
"Not yet!" Dave barked and nosed the Albacore down into a long flat glide. "Shake up the old brains, pal. They don't see us, and can't. We're right in the sun to them. No! They're breaking out that bow gun for another purpose. And I've got a pretty good idea what it is, too."
"What?" Freddy demanded.
Dave nodded his head forward and down.
"To get rid of that plane wreckage that's bobbing around," he said. "Ask me and I'll tell you that the wreckage is all that's left of the courier plane that sent out that SOS. Remember our little unpleasant experience yesterday?"
"I'm jolly well not likely to forget it!" the English youth growled. "What about it?"