He went down with a straight plunge without any splash, and they watched him until he disappeared under the bends.
The mate had his eyes in use as he swam swiftly towards the hole made by the explosion. He watched the shadows upon the coral bottom in the dim light that penetrated the depths. The huge shadow of the brig cast a gloom over the white rock, and at the depth of her keel objects were hard to distinguish, except out beyond where the sunshine filtered down. He knew the location of the hole, and headed straight for it until the black and ragged mouth of the opening showed before him. He had just reached for it when a form shut off the light behind him. At the same instant the dread of something horrible flashed through his brain. He turned instantly to see the giant mouth of a monstrous shark close aboard, the teeth showing white against the dark edge of the throat cavity.
There was but a moment to spare. He must get away in the fraction of a second, and his quick mind, used to emergencies, seized upon the only way possible.
The line about his waist was still slack, and he dove headlong into the black mouth of the hole in the brig's bilge. The opening was just large enough to let him through, the splintered edges raking his back sorely as he entered. Then he turned quickly, hoping to see the monster sweep past.
The outline of the hole showed dimly, a ragged green spot set in inky blackness. He was ready to make a dash outboard, and swam to hold himself close to it, for the tendency was to rise into the black depths of the submerged hull. Inside was total darkness, and the unknown, submerged passages to some possible open hatchway beneath his own vessel's bottom were not to be thought of for safety. He could hold his breath but for a very short time longer, and he was more than twenty feet below the surface of the ocean. Even as he swam his foot struck something solid above him. He watched the hole and had just about decided that the monster had passed when the hole disappeared from view.
He knew he had not moved, for he could feel the stillness of the water about him. With a growing feeling of horror he groped for the opening.
In the total darkness he thought he was losing the instinct of direction. The danger of his position was so deadly that, in spite of his iron nerves, a panic was taking possession of him. To be lost in the hold of a sunken wreck appalled him for an instant. He must act quickly and accurately if he would live. The precious moments were passing, and his heart already was sending the blood with ringing throbs through his head. He made a reach ahead, and as he did so the greenish light of the hole in the bilge came again before him. He struck out for it powerfully. Then it failed again, but as it did so he made out the form that was closing it. The great head of the shark was thrust into the opening, withdrawn again as though to try to get a better position to force its way in, and then came total blackness.
The mate was failing fast. He had been under water more than two minutes. He saw that it was certain death to force the entrance. Outside waited the monster who would cut him to pieces before he could reach the surface and help from his vessel. It was a horrible end. The thought of a mangled form being devoured into the bowels of such a creature decided him. Any death but that. He hesitated no longer, but with maddening haste he swam upward into the blackness, groping, struggling through doors and passages, wildly, aimlessly trying for a blind chance that he might at last come through the hatchway into the sea above.
He had cast off the line to his waist as soon as it came taut, and instantly it flashed upon him that he had severed the last link between himself and his men. On and on he struggled, the bright flashes of light which now began to appear before his eyes, caused by the strain and pressure, made him fight wildly forward, thinking that they came from the light outside. He knew he was lost. The picture flitted before him of the men hauling in the line. Then the silence of the deck in the sunshine and the looks of his shipmates, the case of "lost man." He had seen it before when he was upon the deck, and now it was his turn below. A bulkhead brought him to a sudden stop. He reached upward and found the solid deck. It was no use. He gave one last gigantic stroke forward along the obstruction and started to draw in his breath, which meant the end. Then his head suddenly came out of the water into air, and his pulses leaped again into action.
The pressure was not relieved upon his lungs, and it was some moments before he recovered. Then his great strength came back to him and he began to grope about in the blackness until his feet came in contact with a step. He felt along this and found that it was evidently a companionway leading to the deck above. He put forth his hands into the space overhead and found a solid roof but a foot or less above the surface of the water he was in. Then it dawned upon him that he was beneath the coamings of the hatchway, and the air was that which had been caught under the top as the brig had settled. She had only been sunk about fifty-five hours, and the air had not found its way through the tight cover overhead. It was compressed by the pressure of the water above it. It was only about twelve feet to the surface from where he now rested, and if he could get free he might yet get away safely. The shark was probably below under the bilge, trying to get in the hole and would not notice him if he came up through the hatchway. He could make a dash for the surface, and call for a line before the monster could locate him. The air within the small space was already getting used up while he waited to recover. There were not more than half a dozen cubic feet of it altogether, and he must work quickly if he would be free.