Sailing: Ancient mariner's global challenge: Paul Hayward meets Robin Knox-Johnston, intrepid master of the high seas as he prepares for the most challenging voyage of his illustrious career

Robin Knox-Johnston has a problem with sailing round the world in 80 days. It is not so much that the existing record is 109 days, nor that circumnavigating the globe in such a short time is like 'reducing the 100 metres to seven and a half seconds'. It is how to get his jar of lime pickle on board without Peter Blake, his co-skipper, noticing.

'The damp, the cramped conditions, the diet,' Knox-Johnston, 53, says when asked to list the discomforts of being shoved into a non-stopping 85-foot catamaran for three months. 'The food's freeze-dried. That's a pretty awful diet for 80 days, so I'm going to curry it all and take a bloody great jar of lime pickle. The question is where I'm going to hide it, because Peter says it's too heavy to take.'

Talk about austerity. Knox-Johnston and Blake, two of the world's most eminent sailors, will be joined later this month by a five-man crew for a trans-global race (the Jules Verne Trophy) that would make Hannibal look like an anoraked day-tripper. They will attempt to sail 27,200 nautical miles at an average speed of 16mph, covering 340 miles a day and casting to the oceanic winds all orthodoxies about what is possible in a boat at sea.

Must be mad, you think, as Knox-Johnston leads you to the hangar where lines of be-goggled boat builders are clanking away at the supergun-hulls of the vessel. The mast alone is 102 feet high and cost pounds 160,000 to build over three months. 'There wouldn't be a bigger 'cat' in the world than this,' Knox-Johnston says in his unfailingly affable way as Blake, New Zealand's most intrepid boatman, explains that the crew will sleep in a narrow padded cell 'for noise, vibration and condensation reduction'.

The team will work four hours on and four hours off. Or that is the theory. 'You never get all that time off,' Knox-Johnston says. 'There's always something happening. Meals have to be cooked, radio calls have to be made, there is a log to write, repairs to be made. If we rip a sail we'll all be up working on it.' From experience, the bleary-eyed crew members will be able to measure the speed of the catamaran from the noise of the waves rushing along the hull.

Knox-Johnston, remember, is the man who disproved the theory that it was not possible to sail alone non-stop round the globe. He spent 312 days on his own at sea. 'When I came back,' he says, 'I couldn't walk 200 yards without my ankles giving up.'

He has sailed through numerous hurricanes, and in 1989 recreated Columbus's voyage to the Americas using only 15th century equipment and navigation methods. He belongs in the British tradition of indomitable explorers and adventurers, and two years ago, by way of a change, went climbing with Chris Bonington. Or, 'bloody climbing with Bonington', as he puts it.

For most of us, the images of '80-foot waves' that Knox-Johnston evokes speak only of terrible howling storms and watery deaths. But how about this for a novel view of the planet: 'Look, 70 per cent of the world is water,' he says, 'and if you look at the way the land is laid-out it was designed to sail around. It's the ultimate racing course.' Naturally.

Not that he never gets intimations of mortality. He tells the story of being alone on deck in the southern ocean, 'looking out to see a huge breaking sea coming', and not having time to get below, and climbing up the rigging to escape certain death from being swept overboard, and gazing down as the boat beneath 'disappeared' under a crashing tumult of foam.

'There was me and two masts sticking out of the sea, and nobody else for 2,000 miles. Jesus, that was big. Sheeet . . . what am I doing here, I thought.'

That sense was doubly keen when he climbed down from his pole to discover that he had left the deck hatch open, and so had to spend the next three hours bailing out the boat with a bucket. 'In the Atlantic a 50-foot wave is enormous,' he says. 'It's outside human comprehension.'

That the Jules Verne Challenge is the holy grail of sailing is quickly apparent from the awe with which Knox-Johnston discusses it. He says: 'People always asked me, 'are you going to go round the world again?', and I said I was going to have to find an awfully good reason.

'But then this came up and I thought . . . Oh boy . . . that's 38 per cent off the existing record, and suddenly I was saying . . . phew . . . I've got to go for that.

'Is it possible? The answer is: I don't know. It's a hell of a time to go for. We've got to go at such a high average speed. The boat's certainly capable (it can travel at 25-30mph) and there's no doubt about the crew. They've got an average of two circumnavigations (of the globe) each and they're really well trained. Really experienced. It's not as if we're taking people who only sail at weekends.' Knox-Johnston and Blake say they will not at any stage compromise safety to make up any lost ground.

When the ENZA New Zealand sets off it will follow 'the traditional sailing ships route, which means straight down the Atlantic, turn east round the bottom of Africa and past Australia and New Zealand.'

The crew will survive on a 5,000-calorie-a-day freeze-dried diet and will drink purified sea water. George Johns, a professional cameraman, will transmit pictures to aeroplanes that will pass overhead at specific points, and the only rendezvous planned so far is with a fishing boat off New Zealand, in order 'to dump some stuff'.

'Any guy who tells you he's never afraid at sea is either a bloody liar or is insane,' Knox- Johnston says before he grips his chair and rattles it with excitement at the journey to come. 'All my life I thought going round the world alone would be my biggest challenge because we didn't know if it was possible.

'But boy,' he says, with a humbling, wide-eyed relish, 'this one's running it close.'

The crew of the ENZA New Zealand will comprise Robin Knox-Johnston and Peter Blake (co-skippers), Paul Standbridge, Edward Danby, David Alan-Williams, Donald Wright and George Johns. Johns is the travelling cameraman.

(Photograph omitted)