The current forecasts suggest the tropical cyclone, which has already racked up winds of 200km/h, could strengthen further as it heads south. Even if the system misses New Zealand, big swells and rough seas could still cause real problems for the fleet.
Volvo Ocean Race chief executive Knut Frostad said the race organisers needed to take a cautious approach, as once they leave the New Zealand coastline, there is nowhere for the fleet to hide.
"We're obviously monitoring tropical Cyclone Pam very carefully - this for us is a severe situation. It is a severe situation for New Zealand as well. We have to be very prudent with how we react to it," he said.
The decision to postpone the start of the next leg to Itajai, Brazil was welcomed by the six skippers who will contest the longest haul of the round the world race. The leg through the Southern Ocean and around Cape Horn is already considering the most challenging and dangerous stage of the race, without without having to deal with the power of a super-sized tropical cyclone.
Team Brunel skipper Bouwe Bekking said all the teams were supportive of the delayed start when informed by race management last night.
"It's obvious it is a wise decision," Bekking said.
He felt it didn't need to turn into a "survival race" from the outset of this leg and breakages to any of the boats over the first two days "wouldn't be good for the race".
Despite the delay, a full departure ceremony including a mayoral handover and sailor's parade will go ahead as planned on Sunday.
Organisers will also attempt to hold "a false start" in the form of another in-port race on Sunday to uphold their commitment to sponsors and broadcasters, before the teams return to the dock and wait out the storm. But Frostad said if the weather deteriorates any further on Sunday then plans for the extra harbour race would be canned.
"It is on the borderline of what we think is prudent and safe to do, so we will monitor this continuously," he said.
