America's Cup crash rules still unclear on eve of event

America's Cup race management is yet to confirm what redress the teams will have if they suffer damage through the fault of another team during racing.

The potential for a collision to have a catastrophic impact on a team's campaign was highlighted during last week's practice racing, when Emirates Team New Zealand were forced off the water for two days after sustaining a punctured hull when they were rear-ended by Ben Ainslie Racing.

The setback was minimised with the help of the weather gods, with light air in Bermuda preventing the other teams from getting any racing in while the Team NZ boat was in the shed.

But there are concerns that with the crews racing up to twice a day during the regatta, which gets underway on Saturday, one strike could end a team's campaign.

Team NZ chief operating officer Kevin Shoebridge said America's Cup Race Management (ACRM) are close to finalising the terms for redress if a team suffers damage through the fault of another.

"A lot of those things have been discussed for a long time now - probably over a year and a half. It's very close to being sorted, and hopefully there will be some concessions made if you're the innocent party and you're taken out in a situation like that," said Shoebridge, who described the likely concessions as "meaningful".

"It will be enough to get your boat repaired and back on the racecourse. Take the incident we had last week, we couldn't have done a proper repair, but we could have done enough to get it out there in 24 hours."

But regardless of what opportunity for redress there will be, there is still a very real threat that damage could decide the America's Cup. The reliability of the super high-tech catamarans has proven to be a key challenge for most of the team's in the build-up to racing, with small mistakes having the ability to cause serious headaches.

"There's going to be no delays for start times or racing the next day if you've damage brought on by yourself as such or have a breakdown or malfunction - that's too bad, racing will go on. So the reliability is becoming a big, big issue," said Shoebridge.

"If you're racing two races a day, and you have a breakdown - you can see some big problems. So I think all the teams are working very hard trying to lock down what you've got and trying to make sure they're reliable."

With those reliability issues in mind, Team NZ took a cautious approach to their final day of full training in Bermuda today. The team have a maintenance day scheduled for tomorrow, which is Bermuda's national day, while Friday has been reserved for an exhibition sail, making today the last opportunity for meaningful testing.

Team NZ pulled out of their final practice race against Ben Ainslie Racing after a "soft touch" on their foils.

There were no reports of damage but the decision to quit, while holding a strong lead over BAR, highlighted how racing could be drastically affected by the most random of issues, debris in the water.