“Get those active buoys in the water now!” Rabies snapped.
“What the hell do you think I’m doing back here, playing with myself?” the TACCO snarled. “Here!” He punched the button that fed fly-to points to the pilot’s display.
“Got it!” the copilot said, the report rendered superfluous by the hard banking turn of the S-3. Sixteen minutes later, Hunter 701 had ringed the last position of the submarine with DICASS buoys, which were pouring electromagnetic energy into the water, alternately pinging and listening for a sonar return.
DICASS buoys operated like a shipboard sonar. They provided highly accurate range and bearing information to the AW. The disadvantage was that the submarine could hear the sonar pings, trace back to locate the sonobuoys, and maneuver to evade the pattern. Additionally, using DICASS buoys gave away the fact that someone knew that there was a submarine in the area — and was trying to find it. The submarine, alerted, could exploit every advantage the ocean offered, including anomalous acoustic conditions, to evade contact.
Don’t matter if she knows we know, Rabies thought, banking the S-3B sharply to get into position for the next drop. She already knows about us!
“All buoys sweet and cold,” Harness reported, telling the rest of the flight crew that each buoy was operating properly and that none of the buoys had gained contact on the submarine.
“She can’t have gotten far,” the TACCO muttered. “She only dived ten minutes ago. She’s got to be in the area!”
“Acoustic conditions aren’t the best,” the AW said. Both of his hands were on his head, pressing the earphones tightly over his ears. He took one hand off, reached for his water bottle, and took a swig. “Warm, shallow water. Couple of deep trenches nearby. I’m betting she heads for one of those.”
Sound energy, the TACCO knew, was essentially lazy. Or at least that’s how it had been explained to him in his earliest days as a student naval flight officer. It always seeks out the path that lets it travel the slowest. The actual mechanics of sonar detection and layers in the ocean were explained in a mathematical formula known as Snell’s Law. For the TACCO’s purposes, the “lazy” analogy was sufficient.
Three factors made sound travel faster: heat, pressure, and salinity. Increase any one of those elements in a layer of water, and sound energy would bend away from that layer.
The South China Sea had a hard, rocky bottom. This near the equator, the water on the surface of the ocean was continually warmed by the sun. Wave action mixed the surface water with the layer below it, creating an isothermal layer of warmer water approximately fifty feet deep. The depth varied, depending on time of day and the sea state. At night, the surface of the ocean cooled down slightly. During heavy weather, rougher seas mixed the warm water even deeper into the ocean.
If the DICASS buoys were dropped in the shallow surface layer, the returning pings would be trapped below the warmer area of water and would not return to the DICASS receiver. The AW, knowing the characteristics of this part of the world’s waters, had set his buoys at a depth of two hundred feet, well below the layer.
“Could be anything,” the AW continued. “There’re enough pinnacles and rocks down there to block the return. Or, if she headed in toward the coastline, the water might be too shallow to get a good return. I don’t know if — Wait!” he said suddenly. He pressed the headphones more tightly against his ears.
“Buoy fifteen hot!” he said. “Bearing 310, range four thousand yards!”
The TACCO glanced at his display. “Westernmost buoy. Makes sense — she’s running for the shoreline and shallow water. And for Vietnamese territorial waters. She knows we’re going to be reluctant to follow her in there, regardless of her nationality. I can damn near guarantee that if we shoot a torpedo into territorial waters, we’re going to hit something that’s going to get us in trouble. Murphy’s Law.”
“Lost it,” Harness announced. “She was there, though. I’m sure of it.”
“How the hell did she get that far without us hearing her? She’d have to have been making better than twelve knots — we had to have heard something, at that speed. Let’s lay another pattern,” the TACCO said. His fingers flew over the display, calculating the spacing between buoys, and then punched the information up to the pilot’s display.
“Sir, you’re right,” the AW said thoughtfully, staring at his display. “She makes that speed, I’m going to get her, layer or no layer.”
“But the DICASS contact was solid, right?”
“No doubt. Too hard and sharp to be a biologic,” the AW answered, referring to the possibility that the DICASS buoy could have pinged on a whale or pod of dolphins. Even clouds of shrimp composed of millions of the tiny creatures could reflect back the sound energy from a DICASS buoy.
“And I didn’t hear any biologics. No, I had a sniff of a sub, sir. No doubt.” The AW’s voice was firm.
“Okay, so we chase her down and sink her,” Rabies broke in. “Come on, however she got there, she’s there. Give me the fly-to points.”
“Coming atcha,” the TACCO answered. “But watch it — we’re getting close to the twelve-mile limit.”
“You point, I’ll drive,” Rabies said.
At this point, the TACCO thought ruefully, that was about the best he could manage. He puzzled over the question of how the sub could have slipped through their net of DICASS buoys.
“Come on, it’s just a Tomcat to us,” the Air Boss snapped. “Same weight, same steam settings. What’s taking so long!”
“Uh, sir — that new Captain is down there,” the phone talker said. “He’s giving the flight deck crew a hand. Guess he wants to make sure everything’s copacetic for those birds.”
The Air Boss groaned. “Does he want those JAST birds of his launched or bronzed? Jesus, that’s all we need — a 0–6 ‘helping’ the flight deck crew. Is he on the circuit?”
“Yes, Boss. He’s calling the JAST birds ‘Spook.’”
The Air Boss slipped his headphones on and listened. Sure enough, Batman’s voice was there, talking to the catapult officer on the flight deck frequency.
“Captain Wayne,” the Air Boss said, a note of urgency in his voice. “I think we need you up here in Pri-Fly overseeing this.”
“Roger, Air Boss,” Batman’s voice said, recognizable even through the background howl of the JAST Tomcat engines. “I’m just checking on a couple of-“
“Now, Captain,” the Air Boss heard another voice chime in. He grinned. The Admiral had undoubtedly wondered what was taking so long to launch the JAST birds. He must have turned on the CCTV, seen his former wingman on the flight deck, and extrapolated the reason for the delay.
“Aye, aye, Admiral,” the Air Boss heard Batman say. “On my way up.” The Air Boss watched the captain walk back to the Line Shack, handing his headset to a junior brown-shirted Plane Captain.
“Thank you, Admiral,” he heard a high voice say a few seconds after Batman had removed his headset, thus severing his link with the flight deck radio circuit. The Air Boss suppressed a chortle. He wasn’t the only one who’d been watching Batman leave the circuit.
While he doubted that the Admiral could put a face to the voice, the Air Boss recognized it as belonging to Aviation Boatswain’s Mate First Class Winkler, the yellow-shined handler supervising the launch.
Then “You’re welcome, AB1,” the same voice said gruffly, “And stand by to launch another one of those birds. I have a feeling that the only way I’m going to be able to keep Captain Wayne out of your hair is to get his other bird airborne. With the Captain in it.”
The Air Boss blinked. If he hadn’t already known it, he’d just learned a valuable lesson.
Never underestimate what Admiral Magruder knew.
CHAPTER 11
