SYDNEY (AFP) - Supermaxi Wild Oats XI won its eighth line honours in the Sydney to Hobart race on Sunday, officials said, to become the most successful yacht in the history of the competition.

The Mark Richards-skippered 100-footer crossed the finish line ahead of American newcomer Comanche in the gruelling 628 nautical mile (1,163km) race down the east coast of southern Australia, organisers said.

"An historic 8 #RSHYR line honours - Thank you for all your support," the crew tweeted, after crossing the line at Battery Point in an unofficial time of two days, two hours and two minutes.

Wild Oats XI, one of five supermaxis - the biggest and fastest yachts - in this year's race, was also first across the line every year from 2005 to 2008 and in 2010, 2012 and 2013.

But choppy seas during the race meant the leaders were unable to break the record set by Wild Oats XI in 2012 of one day, 18 hours, 23 minutes and 12 seconds.

The 70th Sydney-to-Hobart bluewater classic drew its biggest fleet since 1994 with 117 yachts.