Winds gusting to around 115 m.p.h. wreaked havoc on the 57th Sydney-Hobart race yesterday with five of the 75 yachts forced to retire within nine hours of the start of the 630-mile race.

The freak conditions, exacerbated by winds generated by bush fires raging on the outskirts of Sydney, produced mini tornados one of which tore into the race-leader Nicorette and bombarded the 79ft yacht with hailstones the size of golf balls. Nicorette's mainsail was ripped and the skipper Ludde Ingvall has a large lump on his head after being hit by a hailstone.

Nicorette, leading the race at the time, was forced to heave-to as the tornado with its associated waterspout hit the yacht. The very localised conditions allowed two of the Volvo Ocean Race competitors, John Kostecki's Illbruck and Kevin Shoebridge's Tyco, to slip past as the crew of Nicorette, the first to finish last year, changed the mainsail.

The start could not have been a greater contrast. The eight Volvo Ocean 60s, for whom the Sydney-Hobart forms part of the third leg of their race around the world, started 200 metres ahead of the 67 other boats in the race and were totally becalmed.

The British skipper Jez Fanstone found the first of the north-easterly zephyrs and his New Corp began to accelerate into the building breeze. Illbruck and Gunnar Krantz's SEB were next with Knut Frostad's Djuice chasing hard but News Corp was first to the turning mark and was awarded a special prize of £3,500 sterling for doing so.

The sea-breeze then collapsed and was replaced slowly by the gradient wind from the south-west. That was before the weather went crazy and Grant Wharrington's 83ft Wild Thing and the 49ft Sting and three other boats were forced to retire.