"Any ideas yet on Sierra Four-five?" Gordon asked.
Rodriguez was seated at his console, leaning forward, eyes closed, right hand lightly touching the headset he wore. For a moment, watching him, Gordon had the feeling that Rodriguez wasn't really there in Pittsburgh's sonar shack, but somewhere else… his mind and focus and being projected out into the black and watery universe beyond Pittsburgh's hull. The green-lit cascade of the sonar's waterfall drew its arcane lines and wiggles on the display screens before him, but Rodriguez appeared to have forsaken the visual world entirely, in favor of one composed entirely of sound.
ST3 Dave Kellerman sat at Rodriguez's right. He was also listening through headphones, but his eyes were on the waterfall… or on Rodriguez. His silence suggested that he'd been left far behind by his more experienced — and talented — mentor.
"I would have to say it's a diesel engine," Rodriguez said after a small eternity of minutes had dragged by. "Pump noises, and a reciprocating engine — cylinders and pistons. What it sounds like, Captain, is a tractor. I know that's impossible…. "
"Not necessarily. The Japanese have used tractors with sealed cabs for underwater work for years. I think those are diesels. They use long hoses from the shore or a boat so they can breathe."
"Could be something like that, I suppose," Rodriguez said. "A Russian oilfield machine, maybe? But what would it be doing out here?"
"Checking that oil pipeline, maybe," Gordon replied. "Or it's something new out of Nikolayevsk, and it's out here on trials or for testing."
Rodriguez reached behind him and made a quick entry on a computer keyboard. "I'm going to run it through the library anyway, and see what comes up. I've never heard anything like this, but there might be something in the record."
All American submarines carried a computer record of the myriad sounds acquired and stored by generations of previous submarine voyages, as well as clips from ASW sonars and seabed SOSUS nets worldwide. In general, any sound could be broken down into one of four broad categories. There were the biologicals, sounds made by the world of life around them — whales singing and shrimp mating and fish making some of the most bizarre sounds ever recorded on the planet. There were the geothermals, also natural sounds, but these produced by nonbiological sources — steam hissing and shrieking under pressure just above a seabed river of molten lava, the clatter of an avalanche, the grumbling sounds of magma moving beneath the thin skin of a deep ocean trench, the outrush of hot water from sea-floor thermals.
The other two categories embraced man-made sounds. The general category included thousands of recordings of everything from fishing smacks to supertankers, and other artificial sources as well — the clank of warning bells on navigational buoys as heard from underwater, for example, or the noises of an oil-rig drilling operation.
The final category was warships, a listing of every ship and submarine so far cataloged, from friendly, neutral, and potentially hostile sources. Using the library, a sonar crew could swiftly ID any given target… and could often pick out characteristics of an individual vessel, old friends as Rodriguez sometimes called them. A good sonar man like Rodriguez often could pick the individual differences that separated one Russian Typhoon, for example, from another, by a system that seemed more magical — or at least parapsychological — than otherwise. A boat's sonar library, however, gave quick, sure matches to almost anything the vessel's sonar might encounter.
"How about the other Sierras?" Gordon asked.
"We've got three main groupings now, Captain," Rodriguez told him. One to the west… that first batch we picked up yesterday, heading south. It looks like they've gathered off of Vlasjevo, four vessels, all small, coastal patrol stuff."
Gordon nodded. They'd followed the progress of those sonar contracts for most of the past twenty-two hours. Whether they'd moved in on Stenki, or were simply part of a routine patrol was still unknown, but it didn't look good for Johnson and Smith and the two Russian agents. At the moment, there was little that could be done.
"The second is moving toward us slowly from the north," Rodriguez continued. "Three large contacts, five small ones. Range thirty to forty miles, best guess. I keep losing them outside of the convergence zones, but they seem to be maintaining a heading dead on toward the Straits."
"Or toward us. And the third group?"
"Sierra Three-three and Sierra Three-four. They're close enough now I can hear their captains jingling change in their pockets while they walk the bridge. A pair of Grisha IIIs. Range approximately five miles. They seem to be idling, not doing much of anything."
A tone sounded from the library, accompanied by the clatter and hiss of the printer spitting out a sheet of paper. Rodriguez snagged the sheet, glanced at it, and handed it to Gordon. "Sounds like we have a match for a Swedish UUO, sir."
Gordon read the printout. More than once in the past fifteen years, the Swedish Navy had picked up unusual sounds off their coast, sometimes deep inside their territorial waters. Sometimes, the sonar contacts were visually identified — as when a Soviet diesel sub ran aground in Swedish waters recently. More often, the contacts were lost… and few were completely identifiable.
Apparently, the Swedes had more than once tracked contacts in and around their naval facilities at Karlskrona and the island of Gotland that had sounded suspiciously like underwater tractors. Similar contacts had been tracked along the Alaskan coast a few years back as well. Naval Intelligence speculated that the contacts represented a very small Soviet submarine with tracks like a tank, designed for beach reconnaissance and amphibious operations. Never identified — at least, not in reports that Gordon had seen — the contacts were called Swedish Unidentified Undersea Objects, or UUOs.
He handed the printout back to Rodriguez. "Is this contact getting closer?"
"Doesn't seem to be, sir. Range is maybe fifteen hundred yards. It was moving when I first picked it up a few minutes ago, but it's been stationary since."
Gordon visualized the chart of the area back in the control room. The UUO, whatever it was, was in the general area of the pipeline the two SEALs had gone out to investigate. Chances were, they would hear the thing themselves and check it out.
He just wished there was something more material he could do to help them. At the moment, though, all he could do was what submariners did best… sit and wait.
Randall clung to the hand with the knife, tucked hard, and somersaulted, pulling his attacker over his back as he rolled. Breaking free, he twisted around as his flippers hit the muddy bottom, stirring up a boiling cloud of silt.
The other diver recovered and came at him again, knife hand extended. The guy was clad in a wet suit, like the two SEALs, but of unfamiliar design. He was big, heavily muscled, and wearing what looked like first-line military underwater breathing gear, either a rebreather or a semi-closed-circuit rig like Randall's with a hell of a good disperser.
Out of the corner of his face mask, Randall saw that Nelson was also locked in hand-to-hand combat with another diver. He could spare no attention for his partner, though, because his own attacker was lunging at him with the knife.
Randall blocked the thrust and got the man's arm in a bonebreaker lock; his attacker countered, though, with a leverage move that flipped Randall away with almost contemptuous ease.
The other diver was strong. Randall was pretty sure these guys must be Spetsnaz, Spetsialnoye Nazranie or "forces at designation," the Soviet military equivalent of U.S. Special Forces and SEALs put together. They were a highly trained elite operating under the Russian Glavnoye Razvedyvatelnoye Upravlenie — the GRU, which ran most Soviet military intelligence operations. If so, he and Nelson were up against men as well trained, possibly, and certainly as deadly as Navy SEALs.