100 Fathoms Below

CHAPTER THIRTEEN

Tim knew well enough that if a Soviet boat spotted them this close, even in international waters, there would be trouble. The line that separated international waters from Soviet territory was a well-established boundary to everyone except the Soviets themselves. They patrolled the waters outside their territory like their own. Publicly they insisted that it was necessary to defend themselves against American and Western European aggression, but in truth it was their way of claiming those waters for themselves, expanding the borders of their empire one nautical mile at a time. If Roanoke was caught even close to the international boundary, it would be forced to surface, and the crew would be arrested and tried for espionage in front of the whole world. Soviet engineers would strip-search the submarine for any technology they might reverse-engineer, while their diplomats made the usual complaints to the United Nations about cynical US imperialism.

He had known from the start that their route to the Kamchatka Peninsula would take them close to the boundary, but he hadn’t expected to run into the Soviets so soon. He had assumed that Roanoke was still a few hundred miles away from territorial waters, but it occurred to him now that he didn’t know where he was, exactly.

Tim’s sonar display utilized spectrograms, which looked like waterfalls of random, colored lights if you didn’t know how to read them. They didn’t work like radar, though. They couldn’t pinpoint and identify enemy boats. Instead, the spectrograms picked up anomalies—noises in the water that could be engines, torpedoes being loaded into tubes, even someone on another boat dropping a pair of pliers on the deck. They were that sensitive. The readings came from the TB-23, the underwater ear that Roanoke was towing—a half-mile-long sonar array that trailed from the stern like the tail of a kite.

The submarine Tim’s sonar had picked up sounded like a Victor. The Soviets had been producing Victor-class subs since the mid-1960s and had been stuck with them ever since. Now they were old and obsolete. Tim could tell it was a Victor from the way it rattled like an old car. He only wished he could nail down its proximity. Passive sonar was good for detecting objects, but terrible for judging how close they were. Active sonar identified everything, practically delivering a Polaroid snapshot, but to engage active sonar now would be the equivalent of sending up a flare. It would alert the Victor to their location immediately, and there was still a chance it hadn’t spotted them yet.

The good news was that Victors didn’t have anything even half as good as Roanoke’s TB-23, although this didn’t mean they were deaf. And their torpedoes worked just as well as Roanoke’s.

“Has it picked us up yet?” Captain Weber asked, leaning into the sonar shack.

Tim said, “It’s hard to say, sir. The Victor is matching our speed and course, but it’s not taking any action to intercept us.”

“Looks to me like we’ve got ourselves a shadow,” the captain said. “Officer of the Deck, rig for ultraquiet.”

Tim held his breath for a moment, something he instinctively did when they went to silent running, even though he knew full well that the Victor’s sonar couldn’t pick up breathing. It couldn’t pick up voices, either, so long as they were kept to a reasonable volume, but other sounds, such as the propeller screw and the nuclear reactor’s active cooling system, could give them away. In ultraquiet mode, the screw would be slowed and the reactor’s cooling system would be switched off, leaving it to be cooled instead by the natural flow of water through the pipes. That was the big stuff. Smaller unnecessary noises would have to be eliminated too—in the quiet ocean, it didn’t take much for a submarine to give away its position. From now on, the galley would switch from preparing hot meals to serving cold sandwiches. The mechanics had to stop whatever they were working on—even the tap of a hammer would be like setting off fireworks. Submarines sailed blind. If a sonar tech heard something, he could track it. If it stopped making noise, he lost it. It was that simple.

Being rigged for ultraquiet made everyone tense, but as a defensive tactic, it worked. One moment, the Victor’s sonar could hear Roanoke; the next, it would hear nothing. It would look to the Soviet boat as if Roanoke had vanished. So long as they didn’t make any sudden turns or pick up speed to more than five knots, they were invisible.

Tim had seen ultraquiet from the other side too. A few underways back, while they were shadowing a Victor, the Soviet sub had dropped off his sonar like a ghost. It was disconcerting, even frightening. He had known that the sub was out there, possibly loading its torpedoes while they scrambled to find it, but it was completely invisible to him. The only way to locate the Victor would have been to use active sonar, but that would effectively have handed them a target to lock on to. It had turned into a waiting game to see who blinked first. In the end, the Victor had chosen to slip away rather than attack. Tim could only hope for a similarly peaceful outcome now.

“Diving Officer, prepare for deep submergence,” the captain said. “Make our depth seven-five-zero.”

“Seven-five-zero, aye,” Lieutenant Duncan replied. “Make our depth seven-five-zero.”

“Seven-five-zero, aye, sir,” Jerry replied. “Making our depth seven-five-zero, aye.”

With Roanoke on alert, it looked as though the animosity between Lieutenant Duncan and Jerry had been shelved for the moment. They were working together seamlessly now. Tim wished it could stay that way, but he knew Duncan well—the harping and picking would start up again at the first opportunity. A tiger didn’t change its stripes, and a bully didn’t suddenly lose the urge to shit on everyone below him.

The dive alarm didn’t sound when they were rigged for ultraquiet, but Tim braced in his seat as the deck tilted beneath him.

“We have to go deep,” Captain Weber said. “Let her follow if she dares.”

“And if that doesn’t work, sir?” the officer of the deck asked.

“Then we’ll still have the advantage. They can’t radio back to their command center about us without rising to periscope depth, and if they do that, we’ll just slip away right under them. If they stay the course at their current depth and keep following us, the thermocline will cut them off from communicating. Spicer, I want a close eye on that boat. If she so much as twitches in our direction, I want to know about it.”

“Aye, sir,” Tim said.

Roanoke descended quickly to 500 feet, then 600, and finally 750. Captain Weber ordered their speed cut to three knots, which would let them run so quietly, the Victor would have no choice but to ping them with active sonar if it wanted to find them.

“Spicer, what’s their position?” the captain called into the sonar shack.

Tim relayed the latest reading to him. “They’re moving slow and quiet, sir, just like us. They might be searching for us.”

“Are they still using passive sonar?” he asked.

“Aye, sir,” Tim said. “They think it’s keeping them undetected, but I’ve got them on the sonar. Just barely, but they are there.”

“Good,” the captain said. “Keep watching them, Spicer. I want regular updates. Helmsman, left full rudder. Steady course three-zero-zero.”

The helmsman replied, “Left full rudder, aye, sir. Making our course three-zero-zero, aye.”

Watching the cascade of colors on his display screen, Tim felt his back and shoulders tensing. He told himself the Victors were obsolete, decaying submarines with antiquated sonar equipment that couldn’t find a honking car in an empty parking lot. He told himself that even if the Victor did find them, it wouldn’t fire on Roanoke unless they had trespassed into Soviet waters. He tried hard not to think about the South Korean jetliner the Soviets had shot down earlier this year, and all the subsequent news reports that questioned whether it had actually been in Soviet airspace. Had that Soviet pilot simply been trigger happy, or had word come down from the Kremlin ordering their military to shoot first and ask questions later? Tim prayed they weren’t about to find out.