Australian teenager Jessica Watson is due to sail into Sydney and into the national spotlight at 2am Saturday (BST), completing her round-the-world voyage.

Thousands will line the quayside and hundreds of boats will take to the water at 11am local time to welcome home the youngest sailor to circumnavigate solo, even though her record will be widely disputed.

Rob Kothe, editor of Sail-World, said her route does not meet the requirements of the World Speed Sailing Record Council (WSSRC), which is the recognised global authority on the subject, and thus she cannot claim to have broken the record set by fellow Australian Jesse Martin in 1999, when he was 18.

But as she sails past the opera house on live Australian television, few of those gathered will care if she has broken the record or not.

Unofficial polls, revealed by the Guardian, show that 75% of Australians believe she is a record breaker.

Martin and fellow circumnavigator Mike Perham will be among those present, as will Australian Prime Minister Kevin Rudd, with events set to rival Sydney’s New Year celebrations.

Jessica’s grandfather Tom Watson says he was never concerned about her safety at sea, but he is concerned about her coping with the media frenzy.

‘I’ve always felt that she’d be OK and she has been OK- she certainly knew what she was about,’ he said.

‘We’re happy for her to be home in one way, but we’re a bit worried about how she’s going to be when she’s been on dry land for a couple of days. It’s going to be an awful big change for her.’

But offsetting that, is the millions she stands to earn as a result of her highly-publicised journey.

One of Rupert Murdoch’s Australian papers has bought her exclusive story for a reported A$700,000 (£430,000) and a TV station has exclusive live rights.

After her 210-day trip, Jessica will go straight into a whirlwind nationwide “Meet Jessica” tour and has a book due out in July.

Her website contains 14 sponsors, with more queueing up, and also does a brisk trade in Jessica memorabilia.

Her yacht, Ella’s Pink Lady, will be on display at the Australian National Maritime Museum in Sydney for a week after her arrival.

Queensland federal backbencher Peter Slipper has nominated the 16-year-old for Young Australian of the Year, which counts tennis player Lleyton Hewitt, MotoGP champion Casey Stoner and SAS trooper Mark Donaldson among its former winners.

‘Jessica is achieving what seemed like the impossible,’ Mr Slipper said.

‘The way that she will inspire and motivate all young Australians can’t be underestimated.

‘In these days of celebrity worship it’s so refreshing to see a role model who’s famous for all the right reasons.

‘Jessica hasn’t achieved glory using her looks or shock tactics – she’s in the spotlight for her genuine talent, courage and enormous sense of adventure.’