"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."