“Slow to one third!” Tremain ordered. “Rig for silent running! Rig for depth charge!”
The helmsman rang up one-third speed and the sound of the electric motors quickly faded to a barely audible hum. Throughout the ship the crew quietly shut and dogged the watertight doors, rigging their spaces in anticipation of the worst while listening to the muffled sound of the escort’s screws overhead. Everyone stared up as if they could see the Matsu’s underside through Mackerel's steel hull and four hundred feet of water.
“The Matsu now bears zero eight eight, sir,” Salisbury whispered.
The sound of the escort’s screws then shifted to a lower pitch and many in the conning tower looked at Tremain as if they expected him to have an explanation for the change.
“She’s slowing,” Tremain whispered to no one in particular. “She’s reached the end of our torpedo wakes, and now she’s slowing to see what she can find. What’s the bearing now?”
Salisbury turned the hydrophone handles a little. “Zero nine zero, sir.”
“How far are we from the firing position now, XO?”
“Eight hundred yards, sir,” Cazanavette answered after leaning over the chart momentarily with the dividers.
The Matsu’s screws continued to change in pitch and volume for several more minutes. Sometimes they grew louder, other times they faded almost too faint to hear.
She must be going in circles, Tremain thought. He wondered why the Japanese captain had not yet dropped his depth charges. That is what he would have done had the roles been reversed. He did not understand why the Matsu’s captain did not unload everything he had on the position marked by the torpedo wakes. It was his best chance of getting them.
Just then Salisbury held up one hand. He turned the hydrophone steering handle slightly and adjusted the sonar headset over his ears. He was listening intently to something.
“Hydraulic noise,” Salisbury finally whispered. “She’s rigging out her sonar transducers.”
Moments later a high-pitched “Ping!” resonated through the water and the hull. It was followed by another, then another as the Matsu’s high energy echo ranging sensors scanned the ocean depths, searching for a reflection off Mackerel's metallic hull.
Even though he had heard it many times before, the eerie sound still sent shivers up and down Tremain’s spine. The resonating pinging was like a kind of taunting, or psychological warfare. It foreboded doom for any boat that was unlucky enough to fall under the piercing beam of sound energy. It established in every man’s mind the fact that they were now the hunted and no longer the hunter.
Tremain surmised his enemy’s strategy. The Matsu’s captain knew that a submarine on battery power would not be going anywhere in a hurry. He could take his time prodding the ocean for his quarry, conserving his depth charges for the final kill once Mackerel’s position was established. Unlike Mackerel, the escort had no oxygen or power constraints, and now that her charge was shot full of torpedoes and heading to the bottom of the Pacific, her captain had nothing to do but preserve his honor and prosecute the malevolent submarine.
The active sonar audibly changed while Tremain glanced at the chart over Cazanavette’s shoulder. The sound now became what seemeded like two “Pings” in rapid succession. There could be no mistake, the Matsu’s probing beam had found them. The sound pulses were bouncing off Mackerel’s hull continuously now and the change caused visible tension to appear on the faces of everyone in the room. The double pings continued and then increased in frequency.
“He’s found us,” Tremain said under his breath, mostly to himself, then immediately wished he had said nothing. He did not need to add to the tension in the room.
The double pings continued to increase in pitch and volume almost incessantly until they were soon audible throughout the entire boat in every space, at every watch station.
“He’s sped up, sir!” Salisbury said, having to shout to be heard over the noise. “He’s closing us quickly from the starboard quarter. He’s too close for a good bearing.”
“Right full rudder, all ahead full!” Tremain ordered. The Japanese captain had them. Their only chance to evade was to try to confuse the Japanese captain.
As Mackerel slowly picked up speed and began to turn right, the noise only grew louder and the pinging became more intense until it seemed like it was shaking the very hull. The Matsu was right on top of them and could not be fooled. Its sonar beam had sought Mackerel out and found her. It knew exactly where she was hiding.
“Picking up splashes, sir,” Salisbury said.
Tremain turned to Smithers. “Pass the word to all stations, depth charges on the way down, brace for impact.” Smithers relayed the information through his phone set as everyone in the conning tower grabbed the nearest handhold. Tremain’s heart was pounding in his chest as he braced himself between the periscopes. He had been through many depth bombings, but the experience seemed to unsettle his nerves more and more each time. He would be lying or mad if he ever said to anyone that it did not affect him. Now, he just tried to concentrate on appearing calm in front of the men around him to take his mind off what was about to happen.
Then, just as fast as they had started, the noise of the screws began to fade, as did the pinging.
“Easy, boys,” Tremain said, recognizing the false sense of security. “Those charges have a good four hundred feet to drop. It’ll be anytime now.”
Suddenly, there was a faint clicking noise outside the hull, then the ocean around the sub exploded.
The powerful depth charges rocked Mackerel like a rag doll. Light bulbs burst into a thousand tiny shards. Pieces of cork insulation showered the men everywhere. Hundreds of loose items crashed against the bulkheads and the decks as metal creaked and vibrated to its very foundation. The lights went out leaving the conning tower in complete blackness.
As the rumblings subsided, Tremain heard moans all around him. His head throbbed from the beating he had received from the number two periscope shaft. He could not see the other men with him in the conning tower, but he could hear their heavy breathing.
“Who’s hurt?” he said into the darkness.
There was no immediate response, so he reached toward the helmsman’s position and clutched what felt like the man’s shirt.
“Rudder amidships,” he said into the blackness. “Slow to one third.”
There was still no response, and Tremain began to wonder if anyone was left alive to carry out his order.
Then someone on the opposite side of the conning tower flicked on a battle lantern and shined it toward the helmsman. Soon the reply came from the direction of the steering wheel.
“Rudder amidships, aye, sir,” the helmsman responded weakly. “Answering ahead one third, steering course three five five.”
Several more battle lanterns flicked on, and Tremain quickly regained his bearings. He noticed that the air had become much more humid, indicating that the air conditioning plant had shut down during the explosions. He touched his forehead to confirm the welt that was rapidly growing there. Next to him, Hubley picked himself up off the deck and returned to the TDC station. All around him men rubbed their sore wounds where valve stems and other protruding equipment had struck them. Such items were everywhere throughout the ship, sometimes in the most inconspicuous spaces. The crew walked by valve stems and jagged equipment everyday without giving it a second thought, but during a depth charging that equipment could become deadly; many submariners had suffered crushed skulls and impaled shoulders.