"Sir, we're traveling at forty knots. Sonar can't hear shit at that speed."
"It is my intention, XO, for us to come to dead slow every… make it every two hours, so that sonar can have a good listen around and we can clear our baffles."
Jorgensen visibly relaxed. "Ah. Aye aye, sir."
Garrett had covered his slip. The truth was, just for an instant, he had forgotten that sonar couldn't hear a damned thing when they were moving at full-ahead.
His hastily improvised coverup actually made sense, though. If a Chinese sub did spot them and try to follow them south, a periodic clearing of the baffles — a maneuver in which Virginia would make a full circle in order to give sonar a chance to "see" the sonar-dead space astern of the boat — should pick it up. And by slowing to take sonar readings every couple of hours, they could create a kind of rough sketch of the water traffic around them, enough to alert them if major surface traffic was closing on their position.
But the fact of the matter, Garrett reminded himself, was that he had slipped up, and that was something no captain could afford. Damn! he thought with a white, savage fury. What's happening to me?
"Have Weps and his boys get on it, XO," he said.
"Aye aye, Captain."
Maybe I was right. Maybe I should step down now, Garrett thought. Relinquish command. Jorgensen's good. He'd get the job done.
His momentary lapse had shaken him. Everyone makes mistakes, forgets something, gets momentarily confused, has a brain fart, as he'd heard it so eloquently described… but when the commander of a submarine had a brain fart, people could die. He had no business remaining in command if he could not keep his mind and his heart focused on the task at hand.
There was, at the same time, a deep and very human part of Garrett that refused to give up the chance to strike back, directly, at whoever it was that was blowing up ships and aircraft in the South China Sea. Whoever it was who had killed Kazuko.
There was one thing, Garrett had discovered long ago, that could relieve the depression when he feared it might be getting out of hand. Not a cure, by any means, but a worthwhile distraction.
Work. He would concentrate on the command of the Virginia, and forget about Kazuko.
At least for now.
"There, sir. There it is again."
Captain Jian pressed the headphone tight against his right ear, eyes closed as he listened. It had been a few years since he'd stood a sonar watch, but the old skills never completely deserted you. He ignored the sonar screen with its cascade of green light and slanted lines, each line representing the movement of a different contact out there in the abyss around them. No, to hear, to really hear a faint and distant contact, was to shut out the visual, to turn one's mind inward, and to reach out with an entirely different sense altogether.
He could hear the soft rushing rumble of the ocean itself, the click and squeak and clatter of its denizens. And there… just at the threshold of hearing, the faintest hint of a pulsing hiss.
"What is your estimate?" he asked the sonar officer.
"This contact is not in our data banks, Comrade Captain. However, it sounds to me much like one of the American Seawolf submarines … but moving at extremely high speed."
"You would not hear it at all if it was not moving at high speed," Jian said. "They say a hole in the water is noisy by comparison." He listened a moment more. "I'm surprised we picked up this much. What do you think the range might be?"
The sonar officer shook his head. "Sir, we were extremely lucky to catch this. It is almost certainly a convergence zone contact."
"I see. So… fifty kilometers… or one hundred… or one hundred fifty."
"Or possibly two hundred. Yes, sir."
"Very well. Stay on the contact."
"Yes, sir. We have designated the target as Ch'ien Nine-five."
Jian left the sonar room and made his way to the main navigational table at the rear of the control room. Elsewhere, Yinbi de Gongji's crew sat or stood at their stations, attentive to their duties and all too obviously trying to ignore the presence of the submarine's captain close by. He said nothing. If nervousness made them even more attentive, so much the better.
Yinbi was currently cruising northwest at a depth of three hundred meters, her position currently at approximately 16° North, 117° East, 160 kilometers north of the tiny island of Huangyan Dao, and 300 kilometers west of the Philippine island of Luzon. She was trailing her towed array, which gave her an uncannily sensitive ear on the ocean to port and to starboard. And she'd picked up that whisper of sound on her starboard side.
Convergence zones were a freakish effect of depth and pressure on sound waves. A submarine captain couldn't count on them, because often the conditions to create them simply didn't exist.
Here, though, they did. Yinbi was crossing the abyssal plain known as the South China Sea Basin, a tongue-shaped depression in the ocean floor between Vietnam and the northern half of the Philippine Islands with depths as great as 4,500 meters. Huangyan Dao interrupted the basin at its eastern end. To the north and to the south, like the two halves of a fish's tail, a deep trench embraced the island of Luzon just off its west coast; the northern part of the trench served as a kind of highway extending from the shallow waters of the Luzon Strait between Luzon and Taiwan, and the main part of the basin.
The point was the basin's depth. Below a couple of thousand meters, the ocean's pressure was so great that it actually served to deflect sound waves, bending them back toward the surface. In a convergence effect, the sound from, say, a fast-moving submarine would hit the high-pressure water and bend up, then hit the surface and deflect down, to be bent up again by the water pressure. The sound waves were focused at specific, clear-cut intervals — usually every fifty kilometers or so — which meant that Yinbi could detect the other submarine when it was fifty kilometers distant, or at any multiple of fifty kilometers out to a range of four or five times that distance. Once the target moved a little closer, Yinbi would lose it. But, if they were lucky, they might pick it up when it entered the next convergence zone, fifty kilometers closer. Jian suspected that the topography of the sea floor — that long, slightly curving trench running toward the north and northeast — was serving as a deep sound channel, creating the convergence-zone effect and also giving him a good idea of the other vessel's exact course.
It was Jian's intent to close with that target, and find out what it was.
Was Ch'ien Nine-five an American Seawolf? Very possible. Very possible, indeed. Chinese Naval Intelligence had already informed him that elements of the American Seventh Fleet were en route through the Luzon Strait, no doubt to provide an intervention force, if necessary, in the Spratly Islands. American attack submarines, like the Seawolf, would most likely precede that force.
And one of those attack submarines would be the target for this entire operation — that and one of the American supercarriers.
Tempting targets indeed, but targets that required extraordinary skill and luck to stalk and kill.
Jian knew he had the skill.
All he needed was a small bit of luck… and that sonar contact just might be the luck he was looking for.