Sailing: Global feat of the space-age flying boat: The record for circumnavigating the world should fall at Ushant tomorrow. Stuart Alexander reports

When Jules Verne decided that 80 should be the magic number of days to encircle the globe he could not have known how many projects would be spawned from that concept. The latest has been to sail around the world, first in the allotted 80 days and now to beat the time of 79 days and six hours set last year in Commodore Explorer by the Frenchman Bruno Peyron.

The prize Peyron won for his amazing feat of seamanship was the Jules Verne Trophy, but his mark will have lasted for only a year. Tomorrow, assuming no last- minute hitches, his record will be beaten by four days as Peter Blake and Robin Knox-Johnston - plus a crew of six - on the 92ft catamaran Enza, cross the start / finish line at Ushant, France.

Ironically, Titouan Lamazou, the man who came up with the idea and sold it to the French government, saw his own attempt in the monster 140ft monohull yacht, Tag Hueur, founder before he even began when the hull was badly damaged during a trial sail in the Adriatic. He has since had to watch from the sidelines while others exploited his initiative.

This is the second attempt for Blake and Knox-Johnston, who were chasing Peyron last year when one of the hulls of their yacht began to break up. They sailed to safety in Cape Town, shipped the boat to New Zealand for strengthening and lengthening - from 85 to 92 feet - and were ready to line up again off Brest in January.

Against them was another Frenchman, Olivier de Kersauson, who had also tried last year and had also seen his boat crumble beneath him. His steed is a 90ft trimaran and he has had to sail in Enza's wake all the way round. He is 2,000 miles behind, so may not beat Peyron's mark, but even if he does he will have to try again if he is not to live permanently with the galling sense of having been overshadowed.

Achieving high speeds in these huge multihulls is easy, keeping the boat together is not. The strain on personnel is considerable. Blake suffered a severe back injury which kept him in his bunk for a week. Now he is fine again, but not fit. Having nowhere to walk for nearly 80 days has meant a severe reduction in his aerobic fitness.

The boat has also taken a beating, but speaking by radio as he approached the last lap, Blake said it was looking remarkably well. Damage to the central 'god pod', which houses all the electronic and navigational equipment, has been contained on a yacht which has a false bottom as a first line of defence against hazards like ice or rogue containers that have fallen off ships.

Twice in the past week Enza has avoided being dismasted because sharp eyes saw that the shackles securing the wire stays were about to fail. But the sails have held up well, as have most of the electronics. Knox-Johnston, as always, has lost his glasses.

Although the first half went well and Enza was on schedule not just to beat the 80 days but perhaps to crack 70, the second half has been hard. They were so far south of New Zealand that the long-range spotter plane was at the limit of its flying time.

They then went to 62 degrees south, perilously close to the Antarctic, in a bid to avoid light winds and shorten the distance. 'We can't go any further south, because that's where our charts end,' was their explanation, making light of what must have been a hair-raising time. They also had to take all the sails down as Enza rounded well south of Cape Horn in 60mph winds and 18-metre waves. Blake described conditions as 'very extreme', the worst he had ever seen.

Blake then had to report a double dose of the doldrums, in that Enza was again slowed while negotiating the Azores high-pressure centre. But last night, in rough and steep seas, she was averaging 18 knots in a south-westerly gale.

They should finish in the early hours tomorrow, less than 75 days since they left. However ungodly the hour, Blake's wife Pippa, with children Sarah-Jane and James in tow, will be there.

(Photograph omitted)