“Energize the topsounder,” he told Stokes. Stokes nodded and dialed in a rotary switch that activated the ultrahigh-frequency hydrophones on top of the sail, which pinged upward, and “listened” for two pings— the first a reflection off the bottom of the ice, the second a reflection off the top. The comparison of the two showed distance to the ice overhead as well as its thickness.
“Looks like a pressure ridge above now, sir,” Stokes drawled. “Thick ice. One-hundred-fifty feet.”
Pacino called over the Junior Officer of the Deck, Lieutenant Brayton.
“JOOD, establish a zigzag search of this area for thin ice.” Pacino drew a square around the omega’s reported position three miles on a side. “Do a search in this block, then search in blocks further outward from the position. Keep plotting ice thickness. And notify me the instant you’ve got thin ice.”
Before Pacino left the control room, he glanced over at the SHARKTOOTH’s topsounders. Still thick ice. 125 feet. The possibility of not finding the OMEGA before she turned around and returned to port suddenly hit Pacino hard — the aching in his neck and shoulders feeling like knives going through him. Knives wielded by one Alexi Novskoyy…
All through the night Devilfish moved back and forth under the ice, the secure pulse topsounder clucking, finding only thick ice and pressure ridges. At 0810 GMT Devilfish had to go down to 350 feet to avoid a deep pressure ridge. Back in the control room, Pacino watched in frustration as the ice got thicker. 90 feet. 120 feet. 130 feet. He glanced at the chart, seeing that this was the furthest block to the east they had yet tried. Obviously the east side of the OMEGA position would turn up nothing but thick ice. It was hopeless. Pacino marked on the chart in bold pencil the area to avoid on the east side and again summoned the JOOD.
“Just thick ice here. Get us back west, to this area. Maybe we’ll get lucky and find the polynya there.” Brayton plotted a course to get the ship to the new search sector.
“One-hundred-fifty feet, thick ice,” Stokes called out from the SHARKTOOTH console. Brayton moved up beside him and told him the new course. Stokes nodded, giving the overhead-ice-thickness readout a grimace before making the rudder order. He looked over to the helmsman.
“Helm, left fifteen degrees rudder, steady course two seven zero.”
After several minutes, for a split second, the ice-thickness readout on the SHARKTOOTH sloped from 145 feet down to five. But as the ship came around, the ice thickness grew back to 175 feet.
“Get back to zero nine zero,” Pacino ordered. Stokes understood. “Helm, shift your rudder!”
“Shift my rudder, helm aye, my rudder is right fifteen degrees, passing course zero one five to the right, no ordered course, sir.”
“Aye, helm,” from Stokes. Pacino patted Stokes on the back as they watched the ice thickness, at the same time Pacino wondering if it had been only a phantom reflection from a void in the ice. But as they got under the thick part of the pressure ridge the ice thickness once again sloped down, from 155 to under five feet in less than thirty seconds. It was an inverted cliff overhead. The polynya.
“Helm, steady as she goes,” Stokes said, trying to contain his excitement. And Devilfish sailed out from under the pressure ridge to the underside of a wide flat lake of thin ice that stretched on for almost four thousand yards. Pacino allowed himself to believe. This had to be it.
“JOOD, map the polynya,” Stokes called to Brayton, who turned on the plot table in the forward starboard corner of the control room. Actually the table was more a flat box with a glass top. Inside the box was a device that received inputs from the ship’s gyro-and-speed indicator and moved inside the box in scale to the ship’s motion in the sea. The device shined a small crosshair upward to the glass. Brayton taped down a large sheet of tracing paper to the glass top and began to plot blue dots on the paper at the crosshairlight’s position every minute-mark of the chronometer. As the ship continued east, the ice remained thin, and Brayton continued with blue dots, connecting them with blue line segments. Finally, two and a half miles east, the ice became thick again, coming down in craggy inverted mountains overhead until it was 190 feet thick. As the boat moved from thin ice to thick, Brayton marked the crosshair and began to plot the dots in orange with orange dashes connecting them and indicating thick ice. With Brayton’s directions Stokes was able to drive the ship in a cloverleaf pattern to explore the boundaries of the polynya — a procedure that could be vital to the ship’s survival… if there was a fire or flooding Devilfish would have to try to make it back to the polynya and surface through the ice. It was essential to know its shape so in an emergency with a loss of the topsounder the captain could make an educated guess where the thin ice was by using the plot table. It was low-tech, dating back to the 1950s, but it worked and would continue to work even if the computers died.
Finally Pacino ordered the ship to bare steerage way under the polynya, affixed his headphone and boom microphone and climbed the step up to the Conn.
“Sonar, Captain,” he said into the microphone, “we’re under thin ice at a two-and-a-half-by-three mile polynya. The OMEGA may be surfaced here. Use maximum positive deflection/elevation and check for signs of him.”
Pacino stared at the sonar panel on the Conn console as he flipped through the displays with the selector keypad. The screen was blank. They were alone.
“Conn, Sonar,” the headphone intoned, “even with max D/E selection we have no trace of a broadband detect on the OMEGA.”
“What about narrowband?” Pacino pressed.
“Cap’n, Sonar, the towed array is dragging at this speed, but it’s still negative.”
The son-of-a-bitch either wasn’t at this polynya or had moved on, Pacino decided.
As the ship cruised at two knots, Stokes keeping it under the thin ice, Pacino returned to the navigation table to try to figure the next search-step. Maybe there was a new intelligence message in the satellite waiting to tell him the OMEGA had gone or been spotted elsewhere. No, an ELF transmission would have called him up from the deep if that were the case. Which meant… the OMEGA still had to be on the surface. Pacino reached into the overhead and grabbed the control ring for the number-two periscope.
“Lookaround number-two scope,” he called out.
“Depth 300 feet, speed two knots,” Stokes called back.
“Up scope,” Pacino said, and rotated the ring a quarterturn. The hydraulics thunked above him as the high-pressure oil fought the sea pressure outside the ship. It seemed to take an eternity for the pole to come out of the well. The smooth stainless steel climbed up and up from the well, until the control module peeked out from the well and climbed even with Pacino’s midriff. Another clunk as the hydraulics stopped. Pacino snapped down the periscope grips and trained the view upward with the left grip. Nothing but darkness, until the view was almost directly overhead. And then there was a faint light, a glow from the thin ice above.
“Off’sa’deck, bring us up slowly to one five zero feet. Two knots.”
Stokes made the orders. Pacino rotated the periscope in slow circles, looking overhead, trying to see any sign of broken ice, any sign of the OMEGA. His earpiece crackled.
“Conn, Sonar, we have a transient, no, a whole lot of transients at bearing two seven five.” Pacino strained to see. Two seven five was on the aftport quarter. Sonar could be hearing an ice raft collapsing the polynya. The polynya might not last if the two ice rafts on either side started to move together. The ice could crush a submarine hull if she was unlucky enough to wait too long on the surface. Maybe the OMEGA had heard the ice shifting and had submerged to avoid trouble…