He held up a hand, and pointed ahead, then opened the throttle, came onto a straightaway course over the hydroplane, rapidly overhauled it and got well ahead. Then, cutting the gun and gliding, as it came up under them, he signaled, and Dick, waiting, ignited a second flare.
All four of the Sky Patrol members gasped as the light blazed out.
Larry looked back at his companions, amazedly.
“It’s—empty—nobody in it!” he cried.
CHAPTER XIX
A BAFFLING DISCOVERY
“Somebody had to be in that hydroplane,” Sandy mused. “They were there to switch on the light, to turn the boat, and to set it on the new course!”
Quickly he peered to the side and back, downward at the water in the place where the first landing flare had settled into the water.
Just a little closer to their position, should have been the spot where the clever miscreant might have abandoned the boat.
Sooner than that, Sandy guessed, the unknown person could not have quit the hydroplane: otherwise the turning from shore would have continued and the hydroplane, instead of proceeding in a straight course away from land, would have swept in a wide circle, round and round.
“There’s no life preserver in the boat either—so that’s what the mystery man used to swim away with—Mr. Everdail’s jewels!” he added.