Team New Zealand, with an oil rig among their hurdles, have had their lead slowly eroded on leg six of the Volvo Ocean Race.
Team NZ's crew on Camper are still in front on day three of the 4800-nautical-mile journey from Itajai in Brazil to Miami, according to the latest position report on Wednesday (NZT).
However, US entry Puma have made up more than 20nm over the previous 24 hours to be just 2nm behind.
In a split fleet, Camper and third-placed Abu Dhabi have elected to hug the coast in a bid to shorten their route.
But their move was hindered by an oil rig laying cables and they were forced to make a detour that cost them 5nm.
The three other teams on the water, all in Juan Kouyoumdjian-designed boats, which have had a clear advantage in broad reaching conditions, are to windward further east.
While there is still 4200nm to go to Miami, the split is making for anxious times for all crews as they wait to find out whose call has been the correct one.
Camper navigator Will Oxley said earlier on Wednesday that conditions were light and it was not clear how the next 24 hours would turn out.
"I have low confidence in the weather models at the moment as they are contradicting each other," he said, adding that the other crews would be in the same position.
"It's a tricky situation, so we just need to focus on boat speed and making the most of any favourable shifts we can get to preserve our lead."
With four legs to complete, Spain's Telefonica are the overall race leaders on points, ahead of France's Groupama, with Team NZ third.