Cyclone warnings and icebergs ensured the entire fleet was on high alert, with organisers setting exclusion zones through which the seven boats are banned from sailing - with the threat of penalty points for those who ignore them.
Despite the conditions, the fleet is still very tightly bunched and Team Alvimedica - a Turkish/American entry - is leading by just four miles from Chinese boat, Dongfeng Race Team.
Team SCA, the all-women crew, are last but only 19 miles adrift of the lead. The 5,200-nautical mile leg is expected to take up to 28 days to complete.
Icebergs in the Southern Ocean are not expected to pose too much trouble, but it is cyclone season in the south Indian Ocean and race director Jack Lloyd imposed new no-sail zones there on the eve of the leg departure on Wednesday to try to avoid one forecast after around 10 days at sea.
Lloyd has acted similarly on the east African coast of the Indian Ocean where there is possible pirate activity.
Race watch producer Mark Covell, a former British silver medallist from the 2000 Sydney Olympics, commented: "The 66 sailors have a real challenge on their hands.
"They left in 40 knots of wind - it was blowing dogs off chains as they say in sailing - in Cape Town. Real boat-breaking stuff.
"And that hasn't let up in the two days sailing since. This is one of the toughest legs in the entire race."