SYDNEY (AFP) - Giant maxi Wild Oats XI faces a tough race to claim her fifth straight line honours win in this year's Sydney to Hobart dash, with commentators predicting a new record in ideal conditions.

The 30-metre state-of-the-art maxi is once again bookmakers' favourite to take top spot in the 628-nautical mile contest, after last-minute repairs Wednesday to scrapes on its keel sustained during a run-in with a fish trap.

Skipper Mark Richards said the damage was only superficial but he needed "absolutely everything going for us in this year's Hobart race", with insiders tipping Wild Oats' 2005 record to fall in strong and favourable winds.

Weather forecasters said tropical Cyclone Laurence, which hammered Australia's west coast this week, would create gusty, northerly conditions for Saturday's race down the eastern coast.

"By Sunday afternoon there will be a 20 to 30 knot nor'-easterly behind the fleet, which will make for fast sailing conditions," a weather bureau spokesman said.

The dash to the finish line would be assisted by strong westerly winds in the notorious Bass Strait, he added.

Cruising Yacht Club of Australia commodore Matt Allen said under such conditions the winner could cross the finish line at Hobart's Constitution Dock in one day and 14 hours -- shaving more than four hours from the race record.

It would be an "exciting thing to watch," Allen said, with lightweight New Zealand super-maxi Alfa Romeo and British sloop ICAP Leopard expected to lay down a tough challenge.

Leopard owner Mike Slade said he wouldn't like to pick a winner from the eight maxis competing in the 100-strong fleet.

"We have our work cut out, but we have our best chance of winning under the predicted conditions," Slade said.

"But God knows what we are going to find out there.

"The weather forecasts are all over the place and apparently it all depends on what ex-tropical cyclone Laurence decides to do."

The fleet, apart from competing for line honours, is also vying for handicap honours, with Australia's Loki tipped as favourite.

The first boat across the line is rarely the overall winner, and for the vast majority of the 100-yacht fleet, the race proper is for handicap position based on the boat's dimensions.

Conditions were not likely to favour the maxis as overall winner, Slade said, with a very small boat more likely to take out the race.

All eyes were on British 72-footer RAN, said Loki's navigator Michael Bellingham, describing it as a "fantastic-looking boat".

Three yachts manned by British soldiers returned from service in hotspots such as Iraq and Afghanistan would also compete in the race as part of the year-long Exercise Transglobe rehabilitation and training program.

The remnants of tropical cyclone Laurence are set to produce big seas for the race but nothing like those of the deadly 1998 event in which six sailors were lost at sea in a powerful storm.

Back then, five yachts sank and 66 boats retired in a fleet of 115 yachts in a marine catastrophe that generated world headlines.

A subsequent inquiry into the race considerably upgraded safety requirements for competing yachts and their crews.