Wild Oats XI and Comanche were Saturday leading a depleted Sydney to Hobart fleet down Australia's east coast, with eight boats retiring including fellow supermaxi Perpetual Loyal after it "hit something".
The Cruising Yacht Club of Australia said Perpetual Loyal had retired from the gruelling 628 nautical mile endurance test citing hull damage, with the 117 starting fleet whittled down to 109.
"The crew believes the yacht may have hit something at about 9:00 pm last night, the hull started delaminating and the yacht took on water in the bow," the race organiser said in a statement.
"The extent of the damage will not be known until the yacht is out of the water."
Perpetual Loyal, one of five 100-foot supermaxis in the race, is the most high-profile retirement so far, with seven other smaller boats suffering broken rudders, sail and hull damage in the tough opening night.
The choppy seas means hopes of breaking the race record, set by Wild Oats XI in 2012 of one day, 18 hours, 23 minutes and 12 seconds, appear to be lost with the leaders about 25 miles behind record-breaking time early Saturday.
The brand-new, cutting-edge Comanche, owned by American technology entrepreneur Jim Clark, flew out of Sydney Harbour at the start on Friday with seven-time line honours winner Wild Oats XI hard on its heels.
But as the boats turned south on the way to the Hobart finish line they encountered strong winds and rough seas, prompting the fleet to spread out as they tried to avoid the worst of the weather.
By morning the winds had eased and were expected to soften further later on Saturday, according to the Bureau of Meteorology forecast.
"We've had a backwards and forwards night; we probably went a little too close to shore. We're in good shape though, and keeping a good eye on them (the leaders)," Andrew Crowe said from Ragamuffin 100, another of the supermaxis.
"The sea is still a little lumpy, we're getting 10-12 knots from the south, and it's starting to go west and light as predicted."
The Sydney to Hobart is a famously unforgiving race which takes crews down Australia's southeast coast, across the notorious Bass Strait and up the Derwent River.
The yachts in the Sydney to Hobart are not only racing for line honours, but the handicap award which takes into account the dimensions of each boat, age and other factors. Each year the race attracts boats ranging in size from 30-footers (9 metres) to 100-foot supermaxis.
Source: AFP