"The old fellow says in his papers that the ship had barely cleared the reef when it sank," said Phil at last. "Perhaps it went further than he thought, Jack. Let's try it out a little further."
The other bent to his oars, and they zigzagged away from the reef, drawing out toward the open sea. Suddenly the sounds in the receivers became softer for a few seconds, but then resumed their former tone.
"Back water, Jack!" exclaimed Phil. "Something happened just then, as though we were skirting along the edge of something down there."
With renewed energy Benton pushed the boat back over its path, and sure enough, in a few seconds the sounds faded. With his hands Phil motioned to turn to the right, but then the signals became loud again, so he hurriedly motioned to the left. This time he was evidently on the right track, for the sounds grew steadily fainter until he could hardly hear them, and then increased as they kept on rowing.
"Back water just a little way, Jack!" said Phil excitedly, and seized the buoy with its attached anchor. This time, as the signals faded out to almost nothing, he dropped the buoy anchor with a splash, and snatched the earphones from his head.
"We've located something, all right!" he exclaimed, as he switched off the battery. "It may not be the wreck we're after, of course, but I'll bet anything that it's _some_ wreck."
"You row and let me listen," said Benton, so Phil took the oars while the other put on the headphones. As Phil rowed toward the buoy, Benton heard the signals diminish just as they had before, and for the first time seemed really convinced that Phil's radio was a practical proposition.
"Back we go for the diving apparatus, then," he said eagerly. "It's early yet, and if they've got it ready we can make a descent before dark."
Phil was as anxious as he, and they both took a pair of oars and made a record trip back to the beach. When the others saw them coming at such a pace they surmised that their trip had been successful, and even before they landed were shouting questions at them.
Phil told them briefly what they had discovered, and they were all eagerness to go out with the raft. It was an ideal day for diving operations, with a calm sea and no sign of a cloud in the sky so, as the apparatus was all rigged on the raft, they started forthwith.