Emirates Team New Zealand are racing to replace a piece of the hull of their boat that was damaged in a crane incident after the opening race of their America's Cup title defence.

The mishap happened late on Thursday when the 75ft Taihoro yacht was being removed from the water after racing.

Team leader Grant Dalton said the multimillion-dollar boat fell some 20 feet on to the support cradle on their team base inside Barcelona's old port.

Dalton said the impact sounded "like a bomb went off". He and skipper Peter Burling inspected the boat after a crew had lifted the tips of its critically important hydrofoils off the concrete ground.

Dalton said on Thursday that the repair job could keep his team sidelined throughout the double round-robin phase that lasts through next week.

But less than 24 hours later he said that enough work had been done overnight to give him hope they could be back on the water sooner than he had first expected.

"It's possible that we could be back out by tomorrow," the CEO of the team and race said.

"I think that were pretty lucky. If it had fallen 200 millimetres to other side it could have been a whole bunch worse, but it fell into the cradle, perfectly into the cradle," he said. "The guys have literally cut out a hole, it looks like the Titanic."

Missing any racing time is a setback, but it should be manageable as long as the boat can be refitted in the coming days or even weeks since as defending champions the Kiwis are guaranteed a spot in the finals held in October.

New Zealand did not participate in their two races scheduled for Friday. That does not impact the standings since their races do not count; they are essentially only for practice to keep the team sharp for the final.