Mark Abernethy - Double back

Mac looked up at Cranleigh as the sub gained speed in its downward trajectory. ‘Sorry, mate. Did you say Plan B?’

‘Yes, sir. Don’t want you punting about on the Timor Sea with that lot patrolling, so we’ll use the diver’s lock, okay? Let’s aim for twenty minutes earlier than -’

‘I’m sorry,’ said Mac, who’d been concentrating on his objectives. ‘Diver’s lock?’

‘Yes, sir. My notes say you’re former Royal Marines? Commandos, I gather, so diving’s not a -’

‘Yeah, yeah,’ said Mac, trying to keep the irritation out of his voice. ‘Combat diving’s in there somewhere.’

One of the most annoying aspects of having a special forces CV was its capacity to create Plan Bs. Mac had completed P-company at Aldershot, the Parachute Regiment’s base, and a year didn’t go by without some planner turning a routine assignment into a chance to make Mac jump out of an aeroplane. It was the same with his completion of the SBS jungle survival course in Brunei, the final component of the brutal swimmer-canoeist program. On the basis of that near-death experience, his various controllers had spent almost a decade ensuring that Mac spent more time in the boonies of South-East Asia than he ever got to spend at cocktail parties.

His combat-diving history had also drawn a lot of Plan Bs, the worst being the time Mac had been ‘volunteered’ by Australia’s reps on IAEA to join French frogmen in a search of the Badush dam north of Baghdad. They’d been looking for the underwater entrance to a nuclear breeder reactor with a highly enriched uranium capacity. That job had combined just about all of Mac’s phobias in a single four-day adventure and he’d almost received an early ride home when he’d asked the IAEA head-shed why they didn’t just lower the water in the dam. Mac’s superior had gone red with rage, but the French thought it was hilarious: Jerst lower ze wort tur! Mais par course!

Now they were talking diver’s locks, the submariner’s version of the pilot’s ejector seat. Mac had done scores of dives from locks, bells and chambers. But there was a major problem with what the XO was proposing.

‘So, Cranleigh – we got a moon tonight?’ smiled Mac, in hope more than expectation.

‘No, sir,’ said the XO, obviously thinking this was good news. ‘She’s darker than the deep.’

‘That so?’ said Mac, coffee rising in his throat.

Something not listed in Mac’s military CV was that he’d done the marines’ hardest frogman section after a few rums. And he wasn’t alone. Like many of Britain’s finest, Mac didn’t like diving at night.

Sitting in the small steel capsule in the ceiling of the torpedo room, Mac tried to stay calm as he ran through his final checks: rebreather unit strapped to his back, face mask, regulator console with compass and depth gauge, and the waterproof gear bag now attached to his belt on the side. He checked the compass, which had an orange luminous bar preset to his course heading, then he put his hand on his Heckler, holstered in a marinised pocket down his right leg.

Below him the XO peered up with curiosity. In the Oberon-class subs the diver’s lock over the torpedo room was generally used in drills for emergency evacuation.

‘Right, sir?’ asked the seaman, sitting on the aluminium stepladder that rose to the lock.

‘Good as gold,’ lied Mac, giving the thumbs-up.

‘When the inside hatch is sealed, the red light will come on,’ said the seaman, pointing. ‘Then I’ll open the exterior valves, sir, and the lock will fill in about six seconds.’

‘Gotcha,’ gulped Mac, his dinner threatening to erupt in the face mask hanging beneath his chin.

‘Then – when the pressure equalises in the lock – I’ll open the exterior hatch and the green light will come on,’ said the bloke, ‘at which point you can push through the hatch, sir.’

‘Thanks, champ,’ said Mac, struggling to control nervous reflux.

‘And I know you know this, sir, but I have to remind you: please breathe out all the way to the surface.’

‘Can do,’ said Mac, dreading the darkness that would soon envelop him like a fog, taking him back into a zone he’d sworn he’d never again enter after the Royal Marines.

The bolts in the interior hatch were slid home, leaving Mac sealed in a space about the size of a car boot, the darkness and clammy heat made worse by the dim red light above Mac’s right eyebrow and the bulky old RAN Drager rebreather weighing down on his back like a tortoise shell.

Keeping his mask off, Mac tried hopelessly to keep his breathing regular as two metallic taps sounded on the interior hatch. The sub was running at about twenty metres and because Mac had been put in the lock at the same air pressure as sea level, he’d have to exhale all the way to the surface to stop his lungs exploding. Some frogmen put their rebreather mask on at this stage, but Mac was breathing so hard that he left his off in case he breathed in by mistake. He’d put it on when he reached the surface and had oriented himself with the shore. A small grating sound filled his ears and then the outside ocean was racing into the chamber, drenching his black bodysuit and filling the lock. Keeping his eye on the red light, Mac took last breaths as the chamber flooded and then the sparkling water that effervesced around him like a large glass of mineral water suddenly switched from an eerie red glow to a bright green hue as the bolts pulled free in the exterior hatch. He checked the depth gauge on the side of the rebreather, which said nineteen metres, meaning it had immediately acknowledged the pressure equalisation of the diver’s lock.

Pushing out of the lock, Mac left the glow of lights, plunging into the inky blackness, a sensation so overpowering that he almost gasped. There was nothing quite like being underwater in the ocean at night. Mac gave a flip of his fins, consciously blowing bubbles as he ascended. His ears screaming, he slowly slapped his fins against the water and concentrated on a gentle exhalation of bubbles, relieving his lungs of the pressure as he rose to the surface.

The blackness closed around him, inducing a nameless fear. The combat-diver section in the Royal Marines Commandos was a watershed for the young men who endured it. Having gone through the basics of free diving, SCUBA and rebreathers, one night the candidates were hauled out of bed to go diving in the dark.

Mac recalled hearing blokes sobbing in the barracks after those dives, and others who requested a return to unit. Diving at night made you face what you feared most and made you do it completely alone. Along with many of the other blokes, by the time they got to the three-hour nocturnal missions around harbours and up rivers, Mac was fortifying himself with grog to get through it. Nothing to be proud of, but there it was.

Making himself blow bubbles, Mac got to nine metres, humming ‘Nadine, honey, is that you?’ to keep him in touch with himself. Almost out of air at five metres, Mac kicked out and pursed his lips, saving the last dregs of expanding air for the final three metres. As his depth dial showed one metre, he kicked and blew the final air from his lungs and came up for air like a cork.

Gasping as he surfaced, Mac scanned the ocean. The night was dark and the sea relatively smooth. A light, warm breeze came from the west, off the Indian Ocean. Treading water, he did a three-sixty and saw no vessels, heard no aircraft. Filling his lungs with air, he acclimatised to his environment.

Lifting the dive console so he could see the compass better, he aimed himself along the course where the compass spindle lined up with the setting made by the orange bar. Besides the compass, Mac also had the GPS on his right wrist, but he would use that later for confirmation – he wouldn’t swim by it.