Mike Sanderson, skipper of the only team racing in a second-hand boat, feared the entire mast could break after the key piece of equipment broke overnight while the team was building a huge lead on the leg from Cape Town to Abu Dhabi.

They were forced to head to Madagascar for repairs, meaning they now have no chance now of reaching the secret 'safe haven' port in time to be transported through piracy-affected waters to the northern Emirates, where the race to Abu Dhabi will resume.

It was a heartbreaking setback for the New Zealander Sanderson and his crew who had established a lead of more than 200 nautical miles on the rest of the fleet in sailing's toughest test.

Their best hope now is to rejoin the race for leg three to their home port of Sanya in China.

Sanya were also forced to suspend racing in the opening leg from Alicante to Cape Town after suffering a hole in her hull, probably caused by storm debris, on Nov. 6.

"We had an awesome night's racing and were making massive gains so we were very upbeat with our progress," Sanderson said.

"The weather was turning for the better and so we were happy in our decisions and general progress.

"As you can imagine we are totally gutted and can't quite believe this has happened when everything was going so well." This is the fourth time that a boat has been forced to stop racing. Three boats, including Sanya, pulled out of leg one but until now the six-strong fleet had been sailing without major problem toward a stop-off point in the Indian Ocean on leg two.

The rest of the fleet will now hope to make it safely to the port for transport to a position near Sharjah on the Northern Emirates coast, from where they will resume the race to Abu Dhabi.

Those measures were taken by race organizers to avoid the threat of piracy in the Indian Ocean.

Leg three runs from Abu Dhabi to Sanya in China but again the boats will be shipped part of the way for security reasons.

US-led Puma now lead leg two following Sanya's withdrawal, with overall race leaders Telefonica of Spain safely in the main pack. The race visits 10 countries in total and finishes in Galway, Ireland on July 8, 2012.