They dived from sunup to sundown. The only rest period for Biff and Derek came when Uncle Charlie dashed into Trinité to replenish the air tanks.
The piles of shucked oyster shells grew higher and higher. No pearls were found. The boys worked desperately against time, but as the first day passed, then the second, then the third, they worked with heavy hearts. The time limit was drawing near.
Dietz made no further attacks. He was content now to fight his battle in the courts. But the pearl fishers knew he was still in the area. They saw his boat from time to time. He was keeping his distance, but he was still watching.
However, even by using binoculars, Dietz would be unable to determine whether the boys located the pearl fishery. He could only learn this by finding out the results of the daily diving. He would have to know what the opened oysters yielded. For this reason, a nightly guard was kept. Although Dietz was going to use the courts, the search party didn’t want him to know if and when they did locate the fishery. Crunch insisted on taking the night guard duty. He also worked during the day. Biff often wondered when the big Indian slept.
Although the danger from Dietz had lessened, Charlie Keene kept reminding the boys of the danger that always awaited them when they were diving.
It struck suddenly and viciously on the fourth morning of their diving.
Biff and Derek were down in forty-eight feet of water. They had been digging out oysters for half an hour. Basket after basket had been hauled up.
Waiting for his basket to be lowered to him, Biff was suddenly spun around by a swirl of water. It felt as if he had been caught in a whirlpool. Biff cleared his mask. He looked around. Coming at him out of the murky dark waters was a giant shark. The killer swept by within a foot, then turned and slashed back.
Biff looked frantically for Derek. He saw his glimmering white shape ten feet away. Approaching Derek was a second shark.
The sharks hadn’t struck yet. It seemed they were inspecting their prey, waiting before their razor-sharp teeth tore at the boys’ bodies. Biff swam quickly over to Derek. He grabbed his arm and pointed. The two huge sharks were motionless, their wicked eyes on the boys.