If the freighter maintained her heading and speed. She had a top speed of only about twelve knots, and a CRRC could easily outsprint her, but in a long chase the advantage lay with the quarry. In this heavy sea, though, her skipper was keeping her speed to an easily controlled wallow, and the Pittsburgh had vectored the team in at just the right angle to maximize their chance of a clean intercept. It looked good.
Judging wind and wave carefully, Morton put the helm over and gunned the battery-powered engine to full throttle. The other six SEALs grabbed hold of the safety lines looped along the rubber boat's gunwales as the flat-bottomed craft slapped and jounced over the cresting waves. Icy spray drenched them all, and visibility was reduced to a wet blur that stung their eyes in salty blasts.
The Kuei Mei loomed huge and high to the left as they cut beneath the leviathan's stern and bumped hard through her wake…
"Conn, Sonar!"
Commander Thomas Frederick Garrett picked up the intercom mike beside the periscope housing and held it to his lips. "This is Conn. Whatcha got?"
"Conn, we have a possible contact, bearing two-nine-nine, designated Sierra One-two."
"What do you mean possible contact?"
"Sir… it's very quiet. More like a hole in the water than anything else. But we picked up some transient mechanicals, and Busy is calling it a sub."
"Stay on it. I'll be right there."
Hanging up the mike, he turned to Lieutenant Commander Keith Stewart and said, "You have the conn, Stew. I'll be in the shack."
"Aye aye, Captain."
The sonar shack was located in a room of its own, aft and on the port side of Pittsburgh's control room. Inside, the overhead lighting had been reduced so the four sonar techs on duty could better watch the vertical cascades of light on their monitors popularly called "the waterfall."
"So show me this hole in the water," Garrett said.
Chief Sonar Tech Wayne Schuster handed him a computer printout. "We've been getting bumps and possibles for maybe five minutes now, Skipper," he said. "And two minutes ago Chesty here was sure he picked up a screw, making slow revs for maybe five knots. But no engine room noise that any of us can hear."
SM1 Chester Andrews nodded. "It was there, sir. I heard it. Then I lost it. And the water out there just sounds… well… dead. I know that doesn't make sense, Captain."
"It makes fine sense, Chesty," Garrett said, studying the printout. It was an analysis of transient noises made by the sonar room computer, affectionately dubbed "Busy Bee." They showed several spikes of noise picked up by Pittsburgh's sensitive, far-hearing underwater ears. The steady, crawling thrum of the freighter's screw was clearly in evidence, as were the sharper, higher-pitched hums of the electric outboard motors on the inflatable boats. There was the low-frequency hiss and rumble of the surface waves. But behind the obvious noise…
The traces were so slight as to be damned near nonexistent… thumps or bumps that could have been anything from a fish burping… to someone dropping a wrench on board another submarine nearby. The characteristics argued against the fish-burp notion. That particular streak on the chart looked mechanical… not like a biological at all.
As for the "hole in the water," Garrett knew all too well that sonar operators, the good ones, relied on senses that were as much psychic, as much pure magic, as anything definable and measurable in the real world of science and high-tech computers. Sonar techs bragged that they still did the actual identification of the noises around the sub themselves, with some help from computer sound archives, of course. Manning a sonar station was far more art than science. A feeling that the water was dead in a certain direction might well indicate that something was there, something extremely quiet.
And in submarine warfare, quiet is always the ultimate advantage.
The question was, if there was another boat out there in the darkness someplace, whose was it? And why was it here? There were only a few possible answers that occurred to Garrett, and none of them was pleasant.
"Captain? Conn" sounded over the intercom.
"Go ahead, Conn."
"Sir, Hammerhead reports they are in position, ready to climb."
Garrett thought a moment. He had the power — the responsibility, in fact — of calling off the SEAL op if a problem arose, one jeopardizing the success and the covert nature of the mission. There was a distinct possibility that the hole in the water was a Chinese sub, one sent to shadow the freighter on the surface.
But so far there wasn't enough to go on. "Pass Hammerhead the word that they're good to go," he said. "And Godspeed."
"Aye aye, sir."
Garrett turned to Schuster. "Can I assist you through maneuver?"
Schuster's brow wrinkled. "Sir, at this point I wouldn't know what to ask for. We don't know the other boat's heading, or even his range, if he's there at all."
"Stay on him, then. If you hear anything more, give me a yell."
"Aye, Captain."
"Carry on." Garrett stepped back out of the claustrophobic enclosure of the sonar shack and walked across to one of the two plot tables aft of the side-by-side periscope housings. The freighter had recently come to a new heading, due south, a course that would take her directly across the Pittsburgh's bow in another ten minutes or so. If she was being shadowed by a sub, the other vessel ought to change course as well and might expose herself to Pittsburgh's sensitive sonar arrays.
"Maneuvering," Garrett said. "Come to new course zero-zero-five, ahead dead slow."
"Come to new course zero-zero-five, ahead dead slow, aye aye, sir," Master Chief Alex DePaul repeated from his station between and behind the planesman and helmsman, forward. Aboard American submarines, every order was repeated back verbatim, a carefully, almost religiously choreographed check that orders had been correctly given and correctly received.
This particular set of orders would bring Pittsburgh onto a course parallel with but opposite to the target freighter… and bring into better play her TB-23 towed sonar array streaming aft.
It might give them just a bit of an advantage if the freighter had a silent shadow.
Morton held the outboard's tiller over as TM2 Ciotti secured the magnetic mooring rings to the hull of the freighter alongside. Ciotti reached well up above the level of the CRRC to give it enough play on the mooring lines so a passing wave wouldn't drag it under… or leave it dangling high and dry against the ship's side. After crossing under the Kuei Mei's stern, they'd worked their way forward down the starboard side, so that they were now secured beneath the loom of the freighter's bridge and deck housing.
All of the SEALs had removed their diving gear— flippers, masks, rebreather units, weight belts — and stowed them in mesh bags secured to the inside of the rubber raider. Still dressed in their death-black wet suits beneath Nomex hoods and flight suits — plus assault vests, UBA life jackets, and black rubber boots— they carried the standard subsurface assault loadout known as VBSS, the Navy's acronym for Visit, Board, Search, and Seizure. Each man carried his primary weapon, for most an H&K MP5SD3 with attached laser optical sights and integral silencer. MN1 Vandenberg was packing a Remington 300 combat shotgun with folding stock and a cut-down barrel. The men also had secondary weapons — sound-suppressed Smith & Wesson "Hush Puppies" — plus spare ammo, flares, strobes, grenades, bricks of C-4 explosives, detonators, chem lights, flashlights, knives, medical and E&E kits, personal Motorola radio sets, and night vision goggles. Each SEAL Team member looked like an invader from another world, hulking, bulky, and decidedly other than human.