Hobart: New Zealand maxi Alfa Romeo won the Sydney to Hobart yacht race on Monday, completing a start-to-finish victory and relegating four-time and defending champion Wild Oats XI to second place.

Alfa Romeo, skippered by Neville Crichton, crossed the finish line at Constitution Dock in Hobart, the capital of the island state of Tasmania, in an unofficial time of two days, nine hours, two minutes, well off the race record due to light winds.

Wild Oats XI, which holds the record of one day, 18 hours, 40 minutes, set in 2005, was expected to finish second later yesterday, about 90 minutes behind, followed by British yacht ICAP Leopard.

Alfa Romeo led the 100-yacht fleet out of Sydney Harbour on Saturday and never relinquished the lead.

The New Zealand yacht made it interesting in the final hours, seeing its lead of more than 37 kilometres on Sunday and early yesterday reduced to just 23 kilometres over Wild Oats XI and its skipper Mark Richards late in the race.

But Alfa Romeo re-established a sizable lead at the end, crossing the finish line to the sounds of the horns of nearby yachts in the harbour and cheers from spectators on shore.

Matched pair

Crichton said several hours earlier that he considered his yacht and Wild Oats XI in a match race, and would follow the Australian yacht if it decided to change its course in an effort to pick up more wind.

"We will cover them whenever we possibly can," Crichton said. "We won't let her go out on a flyer without us being there."

Investec Loyal, which has a crew that includes former Olympic 1,500-metre gold medallist Grant Hackett and world boxing champion Danny Green, was expected to finish fourth early this morning.

Alfa Romeo finished second to Wild Oats in 2005, the yacht's only other Sydney to Hobart, before Wild Oats' four-year reign.

At the back of the fleet yesterday, the smaller, slower boats were finding no breeze in the normally challenging Bass Strait.

"We are in a parking lot," Michael Bellingham, the navigator of Loki, said. "It's time to break out the cards."

The calm conditions were forcing skippers on the slower boats to restrict food and drink.

"We have started to ration water to make sure we have enough," Yendys navigator said on Monday. "The trimmers are no longer allowed to pour fresh water over their winches to keep them quiet. No tea or coffee overnight."

Other yachts, which had only two-day food supplies, were also reporting they were running low on food and water. And some of the slowest boats that haven't entered Bass Strait could face New Year's Eve at sea.