The bell from the Radar Office buzzed angrily.
"Forebridge," the Captain called.
"Fair shook the set up that last one, sir."
"All right, Lewis. I've eased her down. Still holding contact?"
"Yes, sir. Target's dead ahead now, sir, range nine thousand."
"Thank you, Lewis." Back to the Doctor: "I'm dead sure it's a U-boat; it's too small to be anything else. Don't ask me what it's doing in this deserted piece of ocean, but I do believe it's going to give me just what I've always wanted, a single-ship duel between a U-boat and a destroyer."
"What odds would you lay?"
"So near even that I'd have to know the other captain, Doc. As far as the ships are concerned, I'd put my money on the U-boat."
"But you reckon you'll win?"
"Of course. But if he's the man I hope he is, we'll have a wonderful hunt."
"Captain, sir." The First Lieutenant had joined them.
"Hullo, Number One, have we got you out of your bunk?"
"Just turning in, sir, when you altered course. Thought I'd come up and see if you wanted me."
"We've got a possible radar contact on a U-boat. We're chasing dead up his tail, and he's four and a half miles ahead. I don't think I'll get any closer until the weather moderates. It will by dawn in these latitudes. Nine o'clock now; nine hours at fourteen knots, a hundred and twenty-six miles to the southwest when dawn comes — if he doesn't spot us before."
"He's almost certain to do that. He's got radar too."
"But no radar mattress aft. He's got to swing his ship if he wants to get a bearing on anything that's right behind him. If we keep station on him, it's my bet his radar operator will think it's a ghost echo. If we closed up on him, or drew off to one side, then he'd know us for what we are. Am I right?"
"Sounds very foxy to me, sir. If we should scare him into submerging in this sea, our asdic would be pretty useless, and he'd probably give us the slip."
"Exactly, Number One." And to the officer of the watch: "Mr. Mackeson, I want to keep station exactly ten thousand yards astern of the target until four o'clock tomorrow morning." He turned back. "Better get your head down, Number One."
"Good night, sir," the First Lieutenant said.
A few minutes later the Doctor also left the bridge.
Her speed reduced, the ship crept after her quarry — the heart of her purring like a great cat, and the snaking tail of her wake laid flat to the waves. As the Captain turned over the events of the last hour the continuous note of the asdic impinged on his conscious mind.
"Mr. Mackeson. Tell the asdic hut to cease transmissions and to keep a listening watch only." The ping of the underwater detection apparatus under good conditions could be heard at great distances.
Silence again on the wind-swept bridge. Should he break radio silence, signal the Admiralty about the contact? Instinct said no. But what was behind this instinct? Was it because he wanted so badly to fight his battle alone, without interference, that he was refraining from sending a signal until interference could not possibly reach him? To challenge singlehanded such a deadly foe was to risk his ship and the lives of his men.
His target, if it were indeed a U-boat, was obviously going somewhere with a very definite object. A U-boat represented too much of her nation's energy to be permitted to cruise aimlessly far from the convoy routes, and the speed of this boat suggested considerable urgency. At fourteen knots, in this sea, conditions aboard would be extremely unpleasant. Was she going to land agents on the coast of Brazil? To refuel in the neutral Argentine? He wished he knew to what rendezvous she hurried.
Rendezvous? Then he understood! The U-boat was steaming to meet a supply ship in this deserted part of the ocean, or an armed merchant raider, or — his mind boggled at the thought — even a German pocket battleship.
If this were so, it was even more important not to flush the bird too soon. A signal would stand a good chance of being monitored by the efficient German radio service. With stations all the way from Norway's North Cape to Dakar in West Africa, they could determine his position and warn the U-boat and whatever it was going to meet. He must make a signal as soon as the submarine dived, make it very short and hope to get it through before the Germans had time to line up the direction-finding sets. He must get Johnson, the telegraphist, to pass the signal in something less than five minutes, using the emergency prefix which would insure priority. But the U-boat must first be sighted. A report based on a suspicious but unclassified radar echo might cause error and uncertainty in London.
"Mr. Mackeson, how's the target?"
"Two-one-oh; ten thousand, sir."
"Good. Keep it so."
He crossed to the voice pipe to the Radar Ofiice and lifted the flap. "Lewis," he said, "are you getting tired?"
"No, sir. I can carry on until dawn if you wish."
"I'd feel happier. We shan't need you once the light comes."
"Aye aye, sir."
Lewis, the Captain thought, was a great asset. He turned to Mackeson. "Eleven thirty now. I'm going down to my sea cabin, I want to be called at four. Good night, Mackeson."
It was good to get out of his clumsy oilskins. The bo'sun's mate had brought him a thick hot cup of cocoa and he licked his lips appreciatively. The Americans, he had heard, drank coffee on the bridge at sea. He thanked heaven he was in the British Navy as he stretched out on his bunk. The ship rose and fell sedately. He ought to sleep, but sleep had never seemed farther away. Tomorrow he would be trying to kill a violent enemy; and just as certainly the U-boat captain would be trying to kill him. He could at least turn these waiting hours to good account by devoting them to thought — and this might well give him an initial advantage over his adversary.
Sooner or later the U-boat's Kapitan would discover the unwelcome fact that an enemy was sitting on his tail. The conditions inside the boat at that moment leapt to the imagination and brought a smile to his lips. There would be anger, disorder and bitter recriminations, all a poor prelude to battle. It was not to be expected, however, that this would for long impair the efficiency of the very efficient German U-boat service.
The German would almost certainly risk a peep through his periscope. If he could be sure that only one ship was following him, he'd almost certainly attempt to torpedo her with his stem tubes. Assuming that the U-boat would dive while four miles away from the destroyer, the Hecate at fourteen knots would cover the distance in fifteen minutes. This would allow a resourceful U-boat Kapitan plenty of time to plan and execute a torpedo attack. A torpedo would cover the narrowing distance in about two minutes, but it would take five minutes to work out the settings and fire the torpedoes.
Mentally the Captain did his sum. Five minutes for the Kapitan to regain control of his boat after the crash dive. Five minutes to set and fire the torpedoes. A large alteration of the destroyer's course ten minutes after the submarine dived should take it clear of the torpedo attack. But would it? A ship took time to turn, and her momentum would keep her moving in the old direction even though her bow was already turning to the new course. It would be better to give the order for the step aside at eight minutes after the dive.
There was only one point that worried him. Would a U-boat fire torpedoes at a destroyer approaching dead toward him? It seemed a terribly small target at which to aim. But suppose he were deliberately to tempt the German by offering him an easier shot — would that be more likely to draw the enemy's sting? If he altered course by thirty degrees to starboard as soon as the U-boat dived, the Kapitan would think the British ship was trying to avoid making that depth-charge attack which was always so difficult — the one in which the quarry runs straight away from the attacker. Then eight minutes later he would alter the Hecate's course sixty degrees to port. This certainly seemed to be the solution. It was a game of chess played with ships for pieces, and men's lives for stakes.