to the wideband and narrowband displays.
'Those are the fast auxiliaries and escorts,' Jeffrey said, 'heading west to replenish the Reagan carrier battle group.'
'Correct, sir,' Sessions said. 'These thick lines here're the battleship Wisconsin.' The display was labeled across the top like an unraveled helix, showing each bearing several times but from different incoming depression/elevation angles. Jeffrey hit a switch on Sessions' console, then read the screen.
'Blade rate on Wisconsin's four shafts says she's doing thirty-one knots.'
'She's so noisy we hold contact in the surface duct at a hundred nautical miles.'
'Survivable as hell, though,' Jeffrey said, 'in this sort of war.'
'Agreed, sir,' Sessions said. 'The main thing for big surface units is keep moving fast.
These two contacts are our ASW helos.' He tapped a pair of thin lines slanting across the broadband waterfall. 'They just relieved the first ones that were running low on fuel.'
'They doing ladder searches?' Jeffrey said.
'Yes, sir,' Sessions said.
'Dropping sonobuoys or dipping sonar?' 'Intermittent plopping sounds. No pinging yet, so the hostile can't steal echoes off our hull.'
Jeffrey nodded. 'No sign the helos have a passive contact?'
'Negative, Sir, neither one is circling.'
'That would be our cue,' Jeffrey said. 'Let's hope they hold their fire, on the off chance they pick us up. Them's the rules of engagement — no one wants a blueon-blue.' Jeffrey glanced at Ilse, who looked up at him. She was busy rewriting some computer code. Jeffrey thought her lips seemed very sensuous in the subdued control room lighting. Her pupils were nicely dilated. Then he caught himself.
'I've traded e-mails with your onboard systems administrator more than once,' Ilse stated. 'This change will make better use of real-time surface temperature inputs and static-height anomaly data.'
'More accurate water column density gradients?' Jeffrey said.
'Exactly.'
'Um, great.'
'Sir,' Sessions said, 'we also have Sierras 7 and 8, Klakring and McClusky, the ASW frigates on the outer picket line. They're intermittent in the second convergence zone, some sixty nautical miles, as they zigzag in their sectors. But nothing submerged.'
'We know the enemy's out there somewhere,' Jeffrey said. 'Integrity's passive towed array heard him running on air-independent propulsion. The PROBSUB's been upgraded to a CERTSUB.'
'After we picked up their data dump on EHF,' Sessions said, 'when we went back to ' scope depth, I looked at it myself. Faint but clear low-frequency tonals from the fuel-cell reactant circulators, looked like a German Klasse 212.'
'They probably switched to batteries, at least for now.'
Jeffrey knew Integrity was a SWATH — small water-plane twin-hull — a steel catamaran displacing 5,000 tons and 'armed' with a twin-line passive towed array. Fully 6,000 feet long, that gear had 180 acoustic channels and was optimized for hunting diesel subs by their near-infrasonic tonals.
As Jeffrey and Sessions huddled, Wilson walked over. 'Talk to me,' he said.
'Sir,' Jeffrey said, 'allowing for possible variations in enemy course and speed, our target should be somewhere on an arc to the west of us, within striking distance of our weapons, but we have no datum for a shot.'
'And why not, Fire Control?' Wilson said.
'Captain, it's the same old problem we always have with a diesel/AIP running off its silent storage batteries. We can't hear him except for flow noise when we're practically on top of the guy. And we can't go active without giving ourselves away.'
'Now tell me something I don't know.'
Jeffrey winced. 'Well, sir, there's no way his sonar and signal processors can be as good as ours, 'cause his combat payload's small. We know we can run rings around the guy thanks to our nuclear propulsion. We know we can dive deeper.'
'But we can't assume he doesn't know that, since they have boats that do that too.' Jeffrey hesitated. 'We know he has to snorkel eventually and run his noisy diesels, and if we can force him to sustain high speed, his quiet fuel-cell fuel won't last long either.'
'So what do you think his mission is?'
'Could be one of several things. To lob a nuke at Diego Garcia. To lay mines in the approaches.' 'And.:?'
'Could be an anti-surface-shipping patrol, against our sea lines of communications. Could be intel gathering or a commando op.'
'In other words, Mr. Fuller, it could be anything.'
'Yes, sir,' Jeffrey said. He watched Ilse's fingers delicately tap her keys. He noticed she wore no jewelry, though her ears were pierced.
'How long till he's in missile firing range of the atoll?' Wilson said.
'Er, those boats don't have vertical launch capability, sir. The land-attack missiles they fire from the torpedo tubes have a range of about seventy-five nautical miles.'
'Sir,' Sessions offered, 'the Israeli datum combined with Integrity's puts the enemy's mean speed of advance at sixteen knots.'
'Right,' Jeffrey said. 'Since we're ninety miles from Diego now ourselves, that gives us about an hour.'
Wilson snorted. 'Sixty minutes till the base gets nuked?' Jeffrey nodded. 'If that's their intent.'
'You want to count on D.G.'s antiaircraft defenses splashing all those missiles?'
'Of course not, sir.'
'Should we request more backup? Just plain admit that we can't find the guy?'
'Not yet, sir,' ' Jeffrey said. 'We're the best platform to prosecute, and we're in the best position. The air assets have plenty else to do.'
'So what's the call?' Wilson said.
'That's what I've been thinking about, Captain.' 'Well, break it down. How do you think he got this far?'
'I'm guessing he's a lurker, snuck in past Ranger west of here. After she was hit, I mean.' Commodore Morse came over. 'You're saying they planned it this way? Coordinated movements?'
Behind Morse's friendly manner there was a challenge to his tone. Morse had actually gone through the dreaded British Perisher, where they didn't just teach, they aggressively eliminated. The U.K. had fewer SSNs than the U.S.: ten compared to barely fifty — before war losses, that is. The Brits were nearly beaten by unrestricted submarine warfare twice in the last century, and they took the business seriously indeed. Jeffrey wished America had taken the business more seriously these past twenty years — when the U.S.S.R. broke up, the U.S. Navy had had twice as many SSNs as now, but far too many had been retired prematurely and not enough new ones built.
Morse was a foreign guest, Jeffrey told himself, but he was also the most senior man aboard. His interest here was not just academic. Everybody's life depended on it, and once again the U.K. was almost on the ropes. If this new Hot War went on much longer, the badly overworked attack-boat groups might not meet their commitments — the Allied fleets' initial six-month surge capacity was fast running out, the units badly needed maintenance and upgrades, and the Axis knew it.
Jeffrey met Morse's eyes. Morse's expression seemed to say, Go ahead, lad, impress me if you can.
'The problem, sirs,' Jeffrey said, 'is that the helos' air-dropped active sonobuoys don't have much power. If they ping while we listen for echoes, the detection probability would be low'
'That's true,' Morse said.
'Their dipping sonar's better, but not by much. They just don't have the electrical capacity aboard. It would almost be better if we drew back, went deep so the dome wouldn't cavitate, and we pinged at max power, with the helos listening from closer in.'
'Bipolar,' Morse said, 'but with the roles reversed.'
'That's all fine in theory,' Wilson said. 'But…'
