Tremain tried not to think of the straining batteries. After being submerged all morning, they were already quite depleted. Going to flank speed would leave them with very little power for any post-attack maneuvering. He imagined that the electrician on the electric plant control panel back aft was probably already having difficulty maintaining voltage. But there really was no option.
Tremain fought the urge to raise the periscope. The lead destroyers should be inside a mile by now. Depending on the fog conditions he might be able to see them, and maybe even the Kurita. But, he did not dare raise the periscope at this speed. At eleven knots, the water resistance would bend it back like a tree caught in a high wind. And if the scope did not break, the escorts would almost certainly sight the white “feather” of spray it would create on the surface.
“I’m getting a lot of pinging now, sir,” Salisbury reported. “It’s across both bows and moving aft. It sounds like they’re about to pass down both sides of us.”
The pinging could now be heard through the hull. The lead destroyers were close. They were not listening, but rather using active sonar to probe the depths as they drove on at high speed. The pinging grew louder with each passing second.
From the number of echo-ranging pulses in the water, Tremain estimated there were at least four destroyers above them. He silently prayed that their piercing sonar would not detect Mackerel's steel hull.
“They’re passing down both beams, now, sir,” Salisbury reported. He had to shout to be heard over the sonar beams.
Tremain again looked at the chart. According to Caza-navette’s dead reckoning, Mackerel would now be at the outlet of the channel and right in the middle of it, equidistant from the two points of land. With destroyers passing down both beams, he assumed that they had to be inside the enemy formation as well. Now they would also face the danger of being run over by the keel of an enemy ship.
Salisbury’s sonar became useless as the sounds of echo-ranging and screw noises saturated every point on the compass. Nothing was discernible to him and Tremain could only assume that Mackerel had remained undetected. He really did not know for certain, but it no longer mattered. They were here and it was time for action.
“All stop!” Tremain shouted.
Cazanavette nodded in approval. They both watched the speed indicator as Mackerel slowed. It took her almost a minute to slow to five knots, even with the massive water resistance, and it seemed like a lifetime.
“Up scope!” Tremain finally ordered when the speed log moved below five knots.
The scope came up into Tremain’s hands as he met it at the floor, instantly pressing his face to the eyepiece. He waited for the water to rinse off the lens as it poked a few inches above the surface. The water was choppy today, with white caps and rollers, terrible conditions for periscope observations since he would not be able to see past the next wave crest when the scope was in a trough. Tremain cursed as wave after wave slapped against the field of view, obscuring his vision. All eyes in the conning tower were glued to him, waiting for the first report of the enemy.
The lens finally cleared as the scope reached a wave crest. Tremain saw that the fog had partially lifted and had become a broken series of water-hugging clouds. Visibility was good in some directions and poor in others. Tremain panned around quickly, anticipating the next trough.
Off Mackerel's port bow, five hundred yards away, he saw the port side of a four-stack destroyer surging through the seas on a southeasterly course, making at least twenty knots. The destroyer was obviously one of the echo-rangers and Tremain was amazed that it had not yet detected the Mackerel. The rough seas and surface agitation must have been hiding them, he thought, as they cruised along at the shallow periscope depth.
Tremain then swung the scope around to the starboard beam. There he saw another four-stack destroyer less than a thousand yards away, with the same course and speed as her sister. That one had not detected Mackerel either — or at least it appeared not to have detected her. It simply steamed on, heading away to the southeast.
With the two ships past, Mackerel was now inside the formation.
Tremain swung the scope to look up the channel, and was met again by a large roller, which submerged the lens for several seconds. The waves came from the northwest, making it difficult to get a long look on any bearing in that direction. Unfortunately, that was the same direction he expected the Kurita to come from. Tremain cursed as another wave doused the lens. Every time the lens started to clear, another roller engulfed it.
“Joe, do you have any good information about what’s out in front of us?” Tremain shouted toward Salisbury.
“No, sir. I still have active sonars everywhere. In front of us, on both sides, and now behind us. Lots of screw noise in front of us, too.”
Tremain kept his eye to the scope, eagerly waiting for the waves to allow him any small glimpse of what lay ahead. He was looking at bubbles and blue water more than anything else.
Then, finally, the periscope reached the crest of a large roller and briefly afforded him a view beyond. Tremain’s heart skipped a beat as the water ran off the lens and the sharp bow of a Japanese destroyer filled his field of view. It was so close that he could not see any of the superstructure, only the pointed bow as it knifed through the water at high speed, tossing the seas to either side. It was headed directly for the periscope.
“Emergency deep, all ahead flank!” Tremain shouted, slapping up the periscope handles. “Destroyer, dead ahead! Rig for depth charge!”
George Olander heard the order down in the control room and immediately flooded the negative tank, bringing on thousands of pounds of water ballast. Mackerel hesitated in the surface suction forces, then angled downward and surged beneath the surface with her new weight. The spinning screws assisted in driving her deep quickly.
Those in the conning tower held on to anything they could as the deck heeled forward at a thirty-degree angle. The angle was so steep that Tremain grew concerned that the screws might be spinning out of the water. He watched as the needle on the depth gauge began its slow clockwise rotation, passing through the eighty-foot mark.. then ninety feet.. then one hundred feet.
The churning screws of the approaching destroyer became audible through the hull. It was going to be close with Mackerel's stern still shallow enough that it was in danger of being rammed.
The screws grew louder as the depth gauge ticked off each painstaking foot.
When the destroyer finally passed directly overhead, it missed Mackerel's hull by mere feet and the churning eddies spawned by its spinning screws grabbed the submarine’s stern and shook it in a corkscrew-like motion. Everyone breathed a small sigh of relief at having avoided the collision, but they soon regained their anxiety as the wait began for the inevitable depth charges.
Tremain was almost certain that the destroyer had detected them. Their scope must have been plainly visible, he thought, and if the Japanese destroyer had not seen it then it could have easily detected the submarine on the sonar as it passed overhead.
He closed his eyes and imagined what must be happening on the surface. The destroyer would signal the other destroyers to converge on the enemy submarine’s location. Then they would commence run after run of depth charge attacks, and they would not stop until they saw oil and debris from Mackerel’s ruptured hull floating to the surface. After seeing the debris they would drop a few more charges just to be sure.