Just a few feet away, the sonarmen came alive as the ship slowed and their acoustic environment became visible to them again. At ahead flank, they’d made so much noise that they couldn’t hear a thing, but as the ship slowed it became quiet again, and to sonarmen, it was like removing a blindfold after many hours.
Sounds emerged in every direction. Behind them, a distant cargo ship with battered screws steamed in an efficient great circle route across the Pacific. A lonely whale moaned plaintively far to the north. Below them, the tectonic plates of the ocean floor groaned as they shifted.
Through all that, a junior sonarman heard something exceedingly odd on his headphones: a faint pinging. He jerked upright, put his hands over his earphones, and closed his eyes in concentration.
“What have you got?” asked the supervisor.
“Not sure…” he said. “But think it might be active sonar. Straight ahead of us.”
“Oh fuck,” said the supervisor, making a quick note in his logs. He turned a switch so he could listen to the same thing as his watchstander. “Do we have anything else on that bearing?”
“Nothing.”
The submarine, as part of its mission to remain quiet, relied largely on “passive” sonar, meaning they just listened for noise with an array of exquisitely sensitive listening devices. It also had, but rarely used, “active” sonar. This was the science of emitting a pulse of sound into the water and waiting for it to hit something and bounce back. The nature and the timing of the echo could reveal much about the target, most importantly its bearing and distance.
Because of the preternatural quiet of a vessel like the
It was extremely faint, and it took the supervisor a while to hear it, but there it was: a series of regular pings, about one second each and one second apart. Definitely electronic, definitely manmade.
“How does it comp?” he asked.
Another watchstander was furiously keying a computer on the side, comparing the frequency of the pinging signal to their vast electronic library of known active sonars, friend and foe.
“It doesn’t match up to anything,” he said. “But it sure as hell sounds like active sonar.”
“Yes it does,” said the supervisor.
He picked up the microphone, exhaled, and spoke.
“Conn sonar, we have possible active sonar at three-zero-zero, designating Sierra One. Recommend battle stations.”
Jabo jerked his head up at that, and looked at Bannick. He fully expected him to immediately call away battle stations; that’s what he would have done. The Chief of the Watch actually put his hand on the alarm. Bannick hesitated, glanced nervously at Jabo, and then hunched down to look at the CODC, his computerized sonar display. He picked up the mike and spoke into it. “Sonar, conn, I don’t see anything at three-zero-zero.”
The sonar supervisor stepped into control. Jabo sensed some disdain from him toward the young Officer of the Deck. “Sir, I listened to it myself. It’s extremely faint but it’s regular and its electronic. Recommend battle stations.”
“Did you get a match?”
“No!” he said, unable to hide his frustration. “Not yet. But it is without question manmade. We need to call it.”
“I concur,” said Jabo. “Along that bearing, it could be our target.”
Bannick exhaled jaggedly. “Let’s not freak out here,” he said. “Why would our target be using active sonar?”
“You need to tell the captain,” said Jabo. “Now.”
Bannick didn’t say anything, but looked toward the ladder, as if his relief might show up and spare him from having to make any tough decisions. Aggravated, Jabo walked briskly to sonar.
There was a brief look of surprise from the sonarmen as he entered. “Can I listen?” he said, and a watchstander nodded, handing him a set of headphones.
After a few seconds he could hear it — it was impossibly faint, and he gave credit to the man who first heard it. It reminded him of one of those hearing tests the navy made him take once a year. But there it was, a faint, regular electronic beeping. “Shit.”
He took the headphones off and handed them back.
“Where are you going, sir?”
“To tell the captain,” he said.
Just as he reached the door, the watchstander at the middle console stopped him. “Wait…” he said.
Jabo paused.
“It’s gone,” he said.
“Shit!” said Jabo. “Are you sure?”
The sonarman waited, his eyes shut, straining to hear it again.
“It’s gone. Not a trace.”
“Goddamn it!” said Jabo.
He walked back into control where Bannick smirked, having just gotten the word from the supervisor, his under-reaction vindicated. “Now let’s get my relief up here,” he said. “The smell of that bacon is making my stomach growl!”
