The Deep Range - Arthur C. Clarke [47]
The noise generators must have been improved, he decided, since the last time this trick had been tried—or else these whales were more amenable. Only a few stragglers tried to break away, and it was no more than ten minutes’ work to round them up on the right path and scare them back with the subs’ own sirens. Half an hour after the mines had been dropped the entire herd had been funneled back through the invisible gap in the fence, and was milling around inside the narrow corridor. There was nothing for the subs to do but to stand by until the engineers had carried out their repairs and the curtain of sound was once more complete.
No one could claim that it was a famous victory. It was just another day’s work, a minor battle in an endless campaign. Already the excitement of the chase had died away, and Franklin was wondering how long it would be before the freighter could hoist them out of the ocean and fly them back to Hawaii. This was, after all, supposed to be his day off, and he had promised to take Peter down to Waikiki and start teaching him how to swim.
Even when he is merely standing by, a good warden never lets his attention stray for long from his sonar screen. Every three minutes, without any conscious thought, Franklin switched to the long-range scan and tilted the transmitter down toward the sea bed, just to keep track of what was going on around him. He did not doubt that his colleagues were doing exactly the same, between wondering how long it would be before they were relieved.…
At the very limit of his range, ten miles away and almost two miles down, a faint echo had crawled on to the edge of the screen. Franklin looked at it with mild interest; then his brows knit in perplexity. It must be an unusually large object to be visible at such a distance—something quite as large as a whale. But no whale could be swimming at such a depth; though sperm whales had been encountered almost a mile down, this was beyond the limits at which they could operate, fabulous divers though they were. A deep-sea shark? Possibly, thought Franklin; it would do no harm to have a closer look at it.
He locked the scanner on to the distant echo and expanded the image as far as the screen magnification would allow. It was too far away to make out any detail, but he could see now that he was looking at a long, thin object—and that it was moving quite rapidly. He stared at it for a moment, then called his colleagues. Unnecessary chatter was discouraged on operations, but here was a minor mystery that intrigued him.
“Sub Two calling,” he said. “I’ve a large echo bearing 185 degrees, range 9.7 miles, depth 1.8 miles. Looks like another sub. You know if anyone else is operating around here?”
“Sub One calling Sub Two,” came the first reply. “That’s outside my range. Could be a Research Department sub down there. How big would you say your echo is?”
“About a hundred feet long. Maybe more. It’s doing over ten knots.”
“Sub Three calling. There’s no research vessel around here. The Nautilus IV is laid up for repairs, and the Cousteau’s in the Atlantic. Must be a fish you’ve got hold of.”
“There aren’t any fish this size. Have I permission to go after it? I think we ought to check up.”
“Permission granted,” answered Sub One. “We’ll hold the gap here. Keep in touch.”
Franklin swung the sub around to the south, and brought the little vessel up to maximum speed with a smooth rush of power. The echo he was chasing was already too deep for him to reach, but there was always the chance that it might come back to the surface. Even if it did not, he would be able to get a much clearer image when he had shortened his range.
He had traveled only two miles when he saw that the chase was hopeless. There could be no doubt; his quarry had detected either the