Competitors will aim to get a catapult pull through the Indian Ocean, with a tropical storm spinning towards them as they reach Reunion Island and Mauritius past the halfway mark from Cape Town and the United Arab Emirates - an overall trip of some 5,200 nautical miles (NM).
Most sailors would try to avoid such a storm, which could blow up to 70 knots, but the elite professional racers in the Volvo Ocean Race are planning to catch its energy by carefully angling their 20-metre, one-design boats to be spun forward.
For Chinese boat, Dongfeng Race Team - fighting it out in the top four along with Team Brunel, Abu Dhabi Racing and MAPFRE - running through the storm will be an especially tense time.
A track, which connects the mainsail to the mast, detached overnight on Wednesday and bowman Kevin Escoffier had to dangle 15 metres up the rig to carry out a makeshift repair.
The breakage will impact on how smoothly Dongfeng can make sail changes – and possibly cost them many miles against the six opposition boats in the 3,000nm remaining to Abu Dhabi.
One of their most experienced sailors, Sweden's Martin Stromberg, summed up: "With the tropical storm approaching, we'll soon have an idea if the repair is solid enough."
The Volvo Ocean Race, offshore racing's leading global race, will take nine months to complete over nine legs after starting in Spanish port Alicante on October 11. It covers 38,739nm in total, visits 11 ports and every continent, concluding in Gothenburg, Sweden on June 27, 2015.