The signal from the Flag Officer Submarines, Penang, brought such a pronounced wrinkle to the Captain’s forehead that men in the control-room wondered what it was about, particularly when he went to the chart-table with Lieutenant Sato, opened the folio drawer, took from it a fresh chart and placed it over the one already on the table.
The Penang signal informed Yashimoto that a damaged British aircraft carrier with two escorting destroyers had passed through the Suez Canal on passage to Durban for refit and repairs. The carrier and its escorts would call at Mombasa to refuel on the journey south, arriving there some time on November 26/27. I-357 and I-362 were to take station off that port not later than midnight on November 25. The chief telegraphist had not yet heard I-362 acknowledge the signal, reported the Navigating Officer.
Yashimoto looked up from the chart-table, the doubt in his narrowed eyes underlined by dark pouches beneath them. ‘That is bad news, Lieutenant. Coming on top of I-362’s continued failure to report since the convoy attack. Well, this is war. But we shall carry out the attack.’
The Navigating Officer’s ‘Yes, sir’ was unenthusiastic. He had a considerable respect for British destroyers after their recent encounter. Closing his mind to that unpleasant recollection he listened instead to the Captain thinking aloud as he worked on the chart with dividers and a slide rule. ‘Distance to Mombasa 485 miles. At twelve knots surfaced and six submerged we make good 216 miles in twenty-four hours. So passage to Mombasa will be fifty-four hours. It is now 2015 on November 20. We have time in hand.’ He had worked on I-357’s economical speeds. The big 1600-ton submarine was capable of twenty-one knots on the surface and nine knots submerged.
‘Current, sir? The…’ began Sato.
‘I am aware of the current,’ interrupted Yashimoto with a slight show of annoyance. ‘Three knots south-going in the Mozambique Channel. But there is often a counter-current inshore.’
‘Yes, sir. Of course.’ Sato was now apologetic. ‘I only mentioned the current because…’
‘Because you thought I’d forgotten it.’ Yashimoto looked up from the chart, bared his teeth at the young Lieutenant in a humourless smile. ‘Inshore is where I intend to go.’
The Captain’s aggressive intentions were mirrored by the outward thrust of his lower lip. ‘Alter course twenty-five degrees to port. Let me know when we’re within five miles of the land. Then give me a course for Cape Delgado.’ Yashimoto turned away from the chart-table, looked round the control-room and nodded briefly to the men near him before making his way to the conning-tower ladder. There, he found Lieutenant Torago Nangi, the Torpedo Officer, who had taken over from Toshida when the watches changed at 2000.
In the north-west there were distant flashes of lightning, followed by faint rumbles of thunder. These did not concern Yashimoto unduly as he looked into the darkness. Indeed, thinking about the Penang signal, his earlier sense of wellbeing became one of near elation. Having disposed of the problem of Ichiro Noguchi in more senses than one, and being free of worry on that account, he was able to give his mind wholeheartedly to what lay ahead. Not only was I-357 homeward bound, but the Penang signal had banished any fear that she might not find a target before reaching her base.
There was certainly a target now — only five days away — and what a target. An aircraft carrier, the dream of every submarine commander. The escort? Two destroyers? Pity about I-362, thought Yashimoto. That could have made things easier. But an arrogant sense of self-sufficiency brushed the difficulty aside. Earlier in the year, off the Marshall Islands, he had sunk an American destroyer and seriously damaged the heavy cruiser it was escorting in company with another destroyer. That attack had been carried out by I-357 operating alone. He was more than ready to meet the new challenge. It was fortunate, he reminded himself, that I-357 had six torpedoes remaining. Since leaving Penang the expenditure of torpedoes in relation to sinkings had been high, but in a number of instances this had been due to faulty running, technical failures in the weapons themselves. His thoughts went on. There was deep water outside the entrance to Kilindini, the port of Mombasa. That would be in I-357’s favour. The enemy’s time of arrival off the port was an important factor. If it were during the hours of darkness, so much the better. He preferred a night action. There would be two opportunities for attack, the arrival of the carrier and its escorts and their departure. If conditions did not favour the former he could fall back on the latter. That might in any event be advisable since, on the enemy’s arrival, he would have observed the carrier’s course when approaching the port. If there was a British minefield she and her escorts would keep to the swept channel.
He was busy with these tactical problems when the voice-pipe buzzer sounded.
‘Hydrophone cabinet — bridge. Propeller noises on sector red three zero to four zero, sir. Range five thousand yards. Single screw. Slow revolutions. Closing slowly.’ It was the operator on watch reporting from the hydrophone cabinet.
Yashimoto’s mind worked fast. Two and a half nautical miles, it told him. Range closing slowly with I-357 doing twelve knots. So they were overtaking a northbound vessel. Single screw. Slow revolutions. A merchant ship.
He called the control-room. The First Lieutenant answered. ‘Pass the word for action standby,’ Yashimoto’s voice had hardened. ‘Surface action. Have the gun’s crew ready. Tell Lieutenant Toshida I want him up here.’
Yashimoto had not used the action-alarm for fear that its raucous clamour might carry down wind to the target. For the same reason he frowned at the sounds of unusual activity which drifted up through the conning-tower as men below hurried to their stations. Toshida arrived on the bridge, followed by the Coxswain who took over the upper steering position. Yashimoto had already altered course to put the target vessel directly ahead.
In the control-room the Navigating Officer recorded the time in the action log — 2031.
During the next twenty minutes the thunderstorm in the north-west drew nearer, and the range of the ship ahead dropped steadily. By the time it was down to two thousand yards, reports from the hydrophone operator confirmed Yashimoto’s belief that the target was a merchant ship. Making good ten knots, it was on course for Cape Delgado, ninety-five miles distant.
The voice-pipe buzzed urgently. ‘Still no radar emissions, sir.’ Hasumu’s report indicated that the vessel ahead, like most merchant ships at that stage of the war, had no radar.
I-357’s stealthy approach from astern on a dark night could only be detected visually. What was not good was the storm. The closer it came, the more likely it was that lightning flashes might reveal the presence of the submarine. For that reason a submerged attack would have been better. Yashimoto, however, had no intention of using his remaining torpedoes on a merchant ship; their target would be the aircraft carrier. The ship ahead had to be sunk by gunfire. The sooner the better.
He called the hydrophone cabinet. ‘Range now?’
‘Twelve hundred yards, sir.’ It was the voice of the chief operator who had taken over.
Yashimoto spoke to the First Lieutenant by voice-pipe. ‘Gun action stations,’ he commanded. Soon afterwards the gun-hatch below the foreside of the bridge opened and the crew of I-357’s four-inch moved silently to their stations on the forward platform.
To no one’s surprise, for he had excellent night vision, it was Yashimoto who first saw the blurred shape ahead at about the time the hydrophone operator reported the range to be five hundred yards. ‘I see it,’ the Captain exclaimed to the Gunnery Officer beside him. ‘It’s dead ahead. Open fire when the range is down to three hundred yards. Aim at the wireless cabin. It’s abaft the funnel. We don’t want them transmitting an SSSS signal. After that go for their stern gun.’ SSSS was the emergency code for attacked by submarine.