While Fatu was paying out the anchor line, I took the glass and leaned over to see what I could make out. The water was about twelve fathoms deep, and far down beneath the whaleboat's keel I could distinguish the purple coral on the floor of the lagoon. Ofai, the Rangiroa boy, was preparing himself to dive. He coiled a long cotton line in the bottom of the boat, and made fast to one end of it a thirty-pound bulb of lead, like an enormous sinker. Then he adjusted his goggles and went over the side. While he lay in the water, drawing a series of deep breaths, Fatu passed him the weight. He allowed it to sink a yard beneath him, seized the rope between the toes of one foot, and took a grip, high up on the line, with his left hand. "_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."