A close race could be in store for Australia's gruelling Sydney to Hobart bluewater classic, with unfavourable conditions near the finish set to work against the supermaxi favourites.

There are 103 entries, including 28 from overseas, for the 73rd edition of the often brutal 628-nautical mile (1,163-kilometre) slog across the Tasman Sea, which leaves Sydney on December 26.

The weather forecast points to a fast race, ideal conditions for line honours favourite Comanche, one of four supermaxis in the hunt along with Wild Oats XI, BlackJack and InfoTrack.

But the conditions could also see the frontrunners arrive in Hobart's notoriously breathless River Derwent at night.

"It doesn't look good for us in the river. We could spend a lot of time there," Comanche's navigator Stan Honey said.

Ichi Ban's navigator Will Oxley quipped that "between 10pm and 10am is death in the Derwent".

The Bureau of Meteorology's state weather services chief Jane Golding said the race was likely to start in a moderate east or south-easterly breeze around 10 knots.

"The winds will shift around to the north-east during the afternoon, to around 15 knots," she added.

The forecast, if it holds, means last year's record race time of 1 day 13hr 31min 20sec by Australian supermaxi Perpetual Loyal, now InfoTrack, was unlikely to be under threat.

Wild Oats, an eight-time winner, is hoping to make it third time lucky after being forced to retire from the last two races.

It took a blow to its chances when the top of its 45-metre (147-feet) high carbon fibre mast was struck by lightning last week, destroying some of its instruments, but is expected to be ready.

"The goal is to be first, to finish," said Wild Oats skipper Mark Richards.

Medium-sized boats, which expect to arrive at the Derwent in the morning, would be in "red hot" competition for the overall win, Oxley suggested.

"It will come down to boat handling and minimising damage," he said.

"Everyone talks about how much fun it is to go downwind, but in 25 to 30 knots on a TP52 (Ichi Ban), that's a lot of wind on the eastern side of Bass Strait.

"So we will be working pretty hard to look after the boat to get through those conditions."

- New owners -

All the supermaxis this year are Australian owned, after Sydney's Jim Cooney purchased the 100-foot Comanche from American owner Jim Clark less than two weeks ago.

Local media speculated he paid more than Aus$10 million (US$7.7 million) for the yacht.

"It's a once in a lifetime opportunity -- too good to pass up," said Cooney, who is relishing the upcoming battle despite only having handled Comanche several times before the start of the race.

"This year competition is fierce, with the strongest line-up of supermaxis ever seen on one race," he said.

"Depending on conditions, any of the 100 footers could take line honours, it threatens to be one of the best races in the history of the event."

InfoTrack is also in the hands of a different owner, Sydney software developer Christian Beck, a newcomer to ocean racing.

"I've seen the start one hundred times but I've no idea what happens after that," he joked.

One a more serious note, he said that "if the weather is very windy like it was last year I think we have a realistic chance of taking back-to-back line honours".

Last year's overall handicap winner, the Volvo 70 Giacomo, has been renamed Wizard, and is now under the ownership of American brothers David and Peter Askew.

It is tipped to again be a challenger for handicap honours -- the vessel that performs best according to size. Line honours go to the fastest boat.