From the look of things, they still thought the Pittsburgh was in the bottom of the bowl, down near the opening to the Tatar Strait. The line of active-sonar craft were still moving south, now less than three miles north of the coastline and ten miles east of Vlasjevo.
Interesting. That was just about exactly where the Pittsburgh had been at this time yesterday, when Randall and Nelson had done their swim to check for seabed sonar arrays and the Sakhalin oil pipeline.
Was it possible, he wondered, that the Russian timetable was off? Suppose — just for the sake of argument — that a traitor had given away Pittsburgh's timetable. Suppose he'd counted off the hours and days of the voyage … and then forgotten to take into account the change in date, due to crossing the international date line from east to west?
Damn, it almost made sense. Jules Verne had used the
Date Line to his heroes' advantage in Around the World in Eighty Days, allowing them to gain a day in their race when they crossed from west to east. This would be working the opposite way… but it might answer several questions… like why the Soviet ASW vessels had started scouring the southern part of the Zaliv just as Pittsburgh was getting ready to leave, and why the crawler sub had just been moving into position, and been idling on her diesels, breathing through a snorkel, instead of relying on quieter — and shorter-lived-batteries.
The suspected spy or CIA mole might have added up the days and told his KGB controller that Pittsburgh would be checking out that pipeline on Saturday, when in fact it had been Friday.
Wait… that was backwards. Had the spy simply gotten confused?
Well, the date line had confused more than one person in the past. And the fact that they'd caught the Katarina and the packages suggested that some members of the opposition, at least, knew what they were doing.
Whatever the cause, the Russians appeared to be just a little behind the Pittsburgh, closing their trap after the American sub had left the area. They were not stupid, however. They would figure out soon enough that one of their crawler subs had been compromised, and its crew killed. They might have the testimony of Katarina's crew as well; any survivors would have been ruthlessly interrogated.
They knew the ' Burgh was in this general area even if they were mistaken about her exact location, and they would have backup forces in place to stop, if possible, the vessel's escape through the net.
It was a case of blind man's bluff … but one where hunters and prey both were blindfolded, and able to locate one another only by sound.
The nearest sierras were a pair of Komar class patrol boats about two miles to the east, apparently searching the approaches to Vlasjevo. Most of the rest of the hunters were considerably farther off, concentrating their search just north of the Tatar Strait, perhaps ten to fifteen miles away. If there were any other hunters out there, they were … "Conn, Sonar!"
It was ST3 Kellerman. "Sonar, Conn. Go ahead."
"Sir, we're getting noises almost on top of us. Sounds like a helicopter."
"Maneuvering, all stop!"
"Maneuvering, all stop, aye."
"Sonar, let us hear it."
"Aye aye, sir."
The sound coming over the 1MC speaker was muffled, muted almost to the point of inaudibility, but it was distinct, just behind the hissing rush of background noise… a faint, fluttering rhythm like the riffling of the pages of a book.
For the sound of the helicopter to be picked up by the Pittsburgh's sonar, the aircraft had to be hovering just above the surface of the water. Why? What had it spotted? The sea was so shallow, and Pittsburgh was running so close to the surface that it was entirely possible that the periscopes or even the top of the sail had breached a little. Even at night, an aircraft might have spotted the wake and flown in to investigate… or the breach could have been picked up on radar. If they had seen something, the next step would be to lower a dipping sonar and try to detect the 'Burgh directly. And after that …
For a long, long moment, as tension grew to unbearable levels in the control room, the Pittsburgh drifted silently just beneath the surface, slowing with the water's friction until she came to a dead stop. The helicopter hovering just overhead might be plying the surface with searchlight beams. Even fully submerged, something as large as a Los Angeles submarine could leave a telltale wake on the surface, a roiling of the water suggesting something large moving just beneath. By going motionless, the wake could be killed.
But had they been in time?
A submarine's deadliest enemy was another sub… but a close second was a helicopter outfitted for ASW search and warfare. A helicopter was fast and could cover an enormous search area. It could use dipping sonar to actively ping any suspected target, or to lay down a search pattern alone or as part of a larger effort.
And they could carry air-dropped 406mm torpedoes, the same kind Randall had seen mounted on the crawler, and they could put them down by parachute almost directly alongside the target sub. A torpedo fired by another submarine or by a surface warship was set to arm itself after it had traveled a safe distance from the launch tube… and the target boat had a chance to outmaneuver or even outrun a torpedo coming from some distance away.
But an ASW torpedo dropped from a helicopter could go hot and active as soon as it hit the water, and the target would have almost no time at all to maneuver clear.
Minutes passed… and more minutes. The thuttering sound was fainter now, almost swallowed by the vaster sounds of the ocean around them.
"Conn, Sonar. Air contact is moving off."
Gordon released the lungful of air he hadn't realized he'd been holding. "Very well, Sonar. Thank you."
The hunters had missed them, this time.
But the Pittsburgh might not be that lucky the next.
Chief Allison laid his hand against the hull, and smiled. "Okay, gents. We're under way again. I'd guess about five knots."
O'Brien laid his own hand on the bulkhead, but couldn't convince himself that he felt anything other than cold, slightly damp, thickly painted metal.
"So… what was it, you think?" Benson asked. "Why did we stop?"
"Could be the skipper was checking to see if he'd forgotten anything back on the beach," Scobey said, grinning. "You know, car keys, wallet… "
The deck under their feet tipped slightly, angling down toward the bow. "Ah!" Allison added. "And we just went down-planes about five degrees. That means the water is getting deeper. Pretty soon, we'll be out of the amphibious Navy and back where we belong, in the Deep."
O'Brien by this time was beginning to get a feel for how his more experienced shipmates felt about such basic aspects of the universe as land and ocean. Submarines actually operated only within the uppermost skin of the ocean; a Los Angeles boat's operational depth of fifteen hundred feet— just a bit over four times her own length — was a tiny fraction of the typical depth of any ocean. The Okhotsk Deep east of northern Sakhalin reached a depth of over ten thousand feet, and Okhotsk was one of the shallower, more confining of the world's seas.
But submariners thought in terms of the freedom offered by the ocean's great depths. There was at least the illusion of three-dimensional movement through a three-dimensional world, and waters shallower than a couple of hundred feet were prisons, restricting the boat to a two-dimensional plane that made it far easier for the enemy to find and track her.