Comanche leads Sydney-Hobart, fleet brace for gales

American super-yacht Comanche was leading the fleet in Australia's Sydney to Hobart on Saturday, after bolting out of the harbour at the start of the gruelling 628-nautical-mile (1,163 kilometre)race.

Australian rival and 2014 line honours winner Wild Oats XI had initially led in the moments after the starter's horn blew, but was overtaken by supermaxi Perpetual Loyal before Comanche took the lead after unfurling her big spinaker.

"We have the hammer down, doing 29 knots," skipper Ken Read reported as Comanche remained in the lead as she neared Jervis Bay later Saturday, taking advantage of the brisk northerly wind.

"We've got to go fast in these conditions that suit us and put distance between us and the rest.

"The southerly is due in four to five hours. If it is sailable, we should still have the advantage, and take more miles out of the others."

Officials have warned of thunderstorms and gales later Saturday as the fleet travel down the east coast of Australia, saying those at the back of the pack will see the worst of the weather.

"For the leading boats, the further south they can get the better," Michael Logan from the Bureau of Meteorology said.

"But for the back boats that looks like where the gales are and where the change will pack its strongest punch. And the boats furthest south will get the moderating breeze first."