Earlier that morning they had sighted a convoy of two ships. Tracking the ships from a distance on the SJ radar, they had obtained a fairly good solution on the potential targets. Then, just as they had been preparing to go to battle stations, the convoy had changed course and left Mackerel in a disadvantageous approach position. After a short discussion with Cazanavette, Tremain had opted for an end around run in which the submarine would sprint ahead and out of sight of the unsuspecting convoy to lay in ambush somewhere further along its path.
It was normal for the XO to come to the conn whenever the captain was called for, but Tremain sensed something other than duty in Cazanavette’s eagerness. It was as if Cazanavette did not fully trust in him, even now. The episode with the torpedo detonators certainly did not help that any. In the three weeks since Chief Konhausen had made the modifications, Cazanavette had voiced his disapproval more than once. He had treated Tremain with a kind of sadistic professionalism.
“Looks like we’ve regained that convoy, sir,” Cazanavette said. “It bears two eight zero. Range is eleven thousand yards.”
Tremain checked the compass on the bulkhead. Mackerel was heading north. When they had last sighted the convoy it had been heading east, straight for Piannu Pass in the Truk Atoll, still over a hundred miles away. If the convoy maintained its present course, they would soon intercept it, long before it reached Truk where the Japanese had their mighty Central Pacific fortress on Tol Island.
Checking the chart and the radar screen once more, Tremain headed up the hatch to the bridge. There, Carl Hubley and Tee, along with the lookouts, held binoculars to their eyes as they scanned the western horizon for any sign of the convoy.
The sky was hazy, just enough to keep the sun from glinting off the water. The sea rolled in gentle swells, yielding an adequate surface disturbance to hide a periscope well. Tremain guessed that visibility could be no more than ten thousand yards. Conditions were ideal for a submerged attack.
“Ship off the port beam!” The call came from one of the lookouts in the periscope shears.
Tremain looked through his binoculars. Far off to the west, a ship emerged from the haze.
“Get me a bearing, Mr. Hubley, and pass it along to the conning tower.”
Hubley swung the target bearing transmitter around and pointed it toward the ship. He clicked a side button to transmit the bearing to the tracking party in the conning tower.
“Two eight five,” Hubley read off the bearing.
Tremain could hear the SJ radar mast squeaking in its well behind him, as it rotated to point down the same bearing. A few seconds later, the radar operator’s voice squawked on the call box, “Bridge, radar. SJ contact, bearing two eight eight. Range nine thousand five hundred yards.”
“Bridge, conning tower,” it was Cazanavette’s voice this time. “The contact is just visible, now. Two-masted freighter.”
Cazanavette had been watching the ship through the periscope. His height of eye would allow him to see farther over the horizon than anyone standing on the bridge. A few feet of height meant miles of visibility on the ocean.
“Bridge, conning tower.” It was Cazanavette’s voice again. “The second ship in the convoy bears two eight zero by radar, just to the left of the first ship, range ten thousand yards. This one has a smaller return. Possible escort.”
Tremain winced invisibly. He had expected the convoy to have an escort, but the reality of it touched a post-traumatic nerve inside him.
“Battle stations torpedo, officer of the deck,” he said to Hubley.
Hubley immediately keyed the 1MC. “General quarters! General quarters! All hands, man battle stations torpedo!”
The general alarm, a monotone successive fourteen bell gong, bellowed throughout the ship as the crew scrambled to their stations. As was customary during battle stations, Tremain took the conn from Hubley, and Hubley dropped down inside the conning tower to man the torpedo data computer. Tee took charge of the TBT and continued passing bearings on the convoy down to the tracking party. The bearings would be entered into the torpedo data computer, along with the range data from the radar, to refine a firing solution that could be passed on to the torpedoes sitting in the tubes.
Tremain allowed just enough time for the men to reach their stations before keying the 1MC. “This is the captain. Lady Luck has shined her face on us today, gentlemen. We have a large freighter with an escort steaming nine thousand yards off our beam. Remember your training. We’re going in!”
Tremain noticed several of the men on the bridge grin at each other. This was the moment of truth they had been waiting for for three agonizing weeks. The trip to the Caroline Islands had been uneventful as far as the enemy was concerned, but not as far as Mackerel's crew was concerned. Tremain had made them conduct drills during the entire voyage. They had averaged six drills per day, which was twice the number normally prescribed by their former captain. Tremain made them drill from one longitude to another. He made them drill as they crossed the international dateline. He made them drill at all times of the day. With every drill he harped on good practices of basic submarining and banged it into their heads the only way he knew how. Days had turned to weeks, and as the patrol dragged on without sighting any enemy vessels, the crew’s morale began to sag even further. Cazanavette had been growing less cooperative with each passing day, and Tremain was sure that his executive officer was starting to doubt his abilities to find and engage the enemy.
Tremain knew that what they all needed was a target. They needed something to prove that all of their efforts and all of his theories were not a waste of time. Tremain had resolved that he had to find a target no matter how small and sink it for the sake of his crew’s morale. All he needed was a contact. Unfortunately, Mackerel's sector of the Carolines had been starkly quiet. The sector was so quiet, in fact, Tremin had considered breaking radio silence to ask Com-SubPac if there was still a war on. But instead he had chosen to exercise discretion and this morning it had been rewarded. The small convoy that they now tracked had appeared.
“Bridge, conning tower.” It was Carl Hubley’s voice this time, the TDC operator. “We have a good solution on the freighter now, sir, and we’re in a good position to intercept its track.”
“Conning tower, bridge, aye. Stand by to dive,” Tremain replied as he lifted his binoculars to look at the freighter once more. The target’s structure was clearly visible now. He could even see its bow plowing up white water. He did not yet see the escort, but it was out there somewhere.
It must have slipped behind the freighter, Tremain thought. It was time. Any closer and Mackerel's low silhouette would not be able to hide her any longer. She would be sighted by the freighter’s lookouts.
“Clear the bridge!” he shouted.
Anticipating the order, the lookouts slid down from their perches and dropped down the hatch. Within seconds, the last lookout was below, and Tremain keyed the 1MC.
“Dive! Dive!”
Tremain depressed the diving klaxon with his thumb.
“AAOOOGAAAHH!… AAOOOGAAAHH!” It blared in all compartments, and he repeated the order.
“Dive! Dive!”
Tee headed down and was practically knocked off the ladder as Tremain came down behind him, shutting and dogging the hatch with one hand. Then all became abruptly silent as the diesels shut down and propulsion shifted to battery power. The only sound was a faint hissing as the last of the air escaped from the main ballast tanks. The deck lurched backward slightly as the bow planes dug into the water at nearly fifteen knots and Mackerel started her rapid descent beneath the surface.