Ascending in wide spirals, the _Cormorant_ rose to a height of two thousand feet. At that altitude the _Titania_ was dwarfed to the size of a dingy, while the boats looked no bigger than pea-pods. The greater part of the lagoon showed clearly through the water--a pale-green unbroken expanse of sand fifteen to twenty fathoms beneath the surface. Here and there were opaque ill-defined patches that required careful investigation. For twenty minutes the flight continued, Claverhouse swinging the bus to and fro in a succession of short turns, working methodically from the entrance of the lagoon to the part where it almost joined the island itself, while Trevear, with binoculars glued to his eyes, carefully examined the floor of the broad sheet of tranquil water. Suddenly the observer ejaculated an exclamation of satisfaction and jogged the pilot on the shoulder. "Got it!" he yelled, and grasped his camera. "Good enough for a record," he soliloquised, and, drawing a Verey pistol from a rack, he proceeded to fire a green light. That was the signal for the boats to close. The motor-boat towing the whaler and the gig approached the spot, the crews keeping a sharp look-out for the signal that was to indicate that they were over their unseen objective. It was a long task. With feelings of exasperation, Trevear watched the boats pass wide of the mark over and over again, only to be recalled and started on a fresh course by means of pre-arranged signals from the Verey pistol. "There must be a current running round that point," thought Trevear. "Every time they appear to be swept away. Ah! That's better; they've discovered the same thing." He raised a pistol and waited while the boats approached the dark, ill-defined patch on the edge of which lay something of fairly-symmetrical shape. "Good enough!" exclaimed the observer, letting fly with three red lights. "Bring her down, Alec!" he shouted. Claverhouse did so, vol-planing seawards in a steep, exhilarating dive that proved that the master-hand of the ex-R.A.F. bomber had not lost its cunning. Striking the surface with a double bump, the _Cormorant_ taxied in the direction of the boats, from which the mark-buoys had already been dropped. They were now bobbing sedately in an exaggerated curve over the site of the wreck. "Fifteen fathoms!" announced Harborough, as the sea-plane was taken in tow. "We're in luck, if that is the wreck. I bargained for twenty to twenty-five." "She's in a big patch of weeds," said Trevear, "and lying well over on her bilge." "Weeds generally mean mud," remarked Harborough. "Awkward stuff to work in. However, we're lucky to locate the wreck so quickly. By the old-fashioned method of creeping and grappling we might have taken weeks. Stand easy. We'll start diving-operations this afternoon."