The last words were almost cut off by water lapping into his mouth. The huge wave raised by the sudden lifting of the vessel caught them both, and for a moment the two were hidden from sight by a mass of surging green foam. Jim kicked frantically, bearing himself and the man to the surface. Something struck hard against his chest, and, gripping at it with the one hand he had free, he swiftly realized that fortune had been good to him, for it was a buoy, cast loose by the injured passenger himself but a little while before, and now swept to hand at a most opportune moment. He looped his arm over it, and, slipping the other deeper down, hugged the man closer, drawing his head well up on to his own shoulder. It was as well that he had made this hasty preparation, for, of a sudden, the ship beside which they floated soused her bows deep again, and slid farther beneath the surface. She seemed to hesitate, to make one other effort. There came a loud explosion, accompanied by the sound of splintering and rending wood. Air gushed from a mighty aperture which had made its appearance at the point where but a little while before the Spanish passengers had been fighting so frantically; then she plunged to her bed in the ocean. Swift as a dart she shot beneath the surface, leaving in her wake a swirling whirlpool, a twisting vortex into which everything--splinters of wood, spars, and human beings--were sucked with alarming swiftness, and with such force that none could resist it. So it happened that Jim and the passenger once more disappeared from the ken of those who were watching so eagerly. How frantically Jim kicked; how desperately he clung to the buoy and to the man at whose rescue he aimed. The swirling water bearing them both down beneath the surface of the Caribbean in the wake of the vessel almost tore them apart in the course of that desperate struggle. At one moment the pull on the buoy was so intense that he felt as if his arm would be dragged from its socket. An instant later a recoil of the waters swept it back against his face with such violence that his jaw was all but broken. "Done for," he thought. "I can't stand much more of this. My lungs are bursting, my head feels as if it will explode."