"A haere!" ordered Fatu—"Go ahead!"
The diver filled his lungs with air, grinned at us like some goggle-eyed creature of the sea, and let go the gunwale. Coil after coil of line flew over the side, and a train of bubbles rose to the surface, hissing faintly. When the line ceased to run out, Fatu pulled in the slack till it stood taut from the bottom, and made it fast to a cleat. Gazing downward through the water glass, I found that I could see Ofai dimly, in the twilight of the depths. He was swimming close to the bottom, with strange slow motions of his arms and legs; at times he stopped as if examining something, and finally—after what seemed a longer time than any man could hold his breath—I saw him approach the rope, pull himself upright, and heave strongly with one hand. He seemed to shoot upward faster than he had gone down; an instant later his head broke water and he was expelling his breath with the eerie whistling sound I was to know so well. Then he shouted—the long-drawn yodeling cry which announces a lucky dive.
"Never have I seen shell of such a size!" he exclaimed, as he handed up a great coral-encrusted oyster and came clambering over the side. "It grows everywhere—the bottom was covered as far as my eyes could see!"
My uncle was opening the oyster with the blade of his clasp knife. It was a rough, roundish thing, uncouth to the eye, and a full eight inches across. He cut the muscle, felt skillfully but vainly for pearls under the fringe, tossed the soft body overboard, and handed the shells—still attached at the hinge—to me. Craning their necks to see, the natives exclaimed with wonder. When closed, the oyster might have been mistaken for an ugly lump of coral, picked up at random on the floor of the lagoon; when open, it displayed the changing opalescent shades of mother-of-pearl, fringed with a band of gold.
"Get up the anchor," ordered Uncle Harry; "we'll try again, a hundred yards farther on."
"There would be a sensation on Tahiti," he went on, turning to me, "if you showed the traders that shell! It's worth twenty dollars a ton more than the black-lipped variety, and the books say that it produces a great many more pearls. We'll do a bit of prospecting to-day, mark the best places, and let the men begin diving in the morning."
We wandered on for several hours, examining the bottom at each halt and marking the more likely spots with a small buoy, moored to the coral with a few fathoms of line. By mid-afternoon, our work seemed finished—we had found more shell than our men could bring up in all the months ahead of us. Our final halt was close to the reef, and there, in about ten fathoms of water, Ofai went overboard for the last time that day.
The coral was light-colored at this place and I could see every motion of the diver beneath us. Suddenly, when he had been about a minute under water, I saw him crouch and disappear in a crevice of the rock, and an instant later a long moving shadow passed beneath the boat.
"E mao!" exclaimed Fatu. "A shark!" My uncle sprang to the side.
I leaned over with the rest, watching with acute suspense to see if the shark would move away. No—he had seen Ofai and was turning back toward the deep crevice in which the diver had taken refuge. Then the shark rose toward us and we saw him clearly—longer than our boat, livid-brown and hideous. An exclamation of horror went up from the men. There seemed nothing we could do. Thirty seconds passed; Ofai had been under water a minute and a half. My uncle had reached the limit of his endurance. He spoke to Fatu sharply: "Your goggles! That knife! The other weight!"