Team New Zealand's preparations for this month's America's Cup have gone from bad to worse today after the Kiwi boat sustained damage after being rear-ended by British team Land Rover BAR during practice racing.

The Kiwi boat has suffered damage to the rear of its hull after the Brits, skippered by Ben Ainslie, ran into the back of Emirates Team New Zealand during a pre-start manoeuvre - an action helmsman Peter Burling described as "unnecessary".

The damage could keep Team NZ off the water for several days.

BAR skipper Ben Ainslie responded to the collision, with an apology and a light-hearted reference to the ding.


''Bit of a love tap racing hard with @EmiratesTeamNZ,'' Ainslie tweeted.

''Sorry guys and hope you're back on the water soon.''

The incident occurred after Burling had done a good job securing the favoured leeward end of the line and shutting out Ainslie and the Land Rover BAR boat.

"It was a bit of a shame in the last pre start we had the leeward end of the line pretty locked down, Ben was quite late and just ran straight into the back of us," said Burling.

"It's just unnecessary a week out from the America's Cup. We are all here to learn and it's a shame we have a pretty big metre dent now in the back of our nice boat.

"[Ainslie] went straight in under the media pod with his windward bow and right down the inside of the leeward hull, so there is a pretty good dent there. You can definitely see it has punctured right into the cockpit right around where my steering wheel is," continued Burling.

Team NZ chief executive Grant Dalton said with America's Cup racing set to begin in just 10 days time, it is a set-back the team cannot afford.

"We know Ben well, he is a good guy but frustration is obviously getting to him and the red mist came down and it's a lot of damage in a time we can't afford it."

Today's incident comes after Team NZ missed yesterday's opening day of the final practice racing window after shredding their rudder before the racing began for the day. While they were able to swap out the damaged rudder and return to the course, they missed their racing slots for the day.

Heading into this week's crucial five-day block of practice racing, Team New Zealand sailing coach Ray Davies told the Herald it was important the crew made the most of their opportunities this week.

Today's collision was a bitter end to an otherwise good day on the water for the Kiwi syndicate. Team NZ won both of the races it sailed against Land Rover BAR earlier in the day and Groupama Team France after both Oracle and Softbank Team Japan refused to race against the Kiwi team.

"Up until the last race with BAR we had a bloody nice day, we got the boat around the track really well, in really nice yachting conditions, but very unfortunate to get a hole in the boat on a practice race. I dont think Ben will be feeling too happy about it at the moment," said skipper Glenn Ashby.

The Team NZ shore crew were waiting at the dock to retrieve the boat and will now be working around the clock to get the boat back out on the water as soon as possible.

The British team reported they had sustained limited damage to their bow in the collision.

The incident on day two of practice racing comes after Team NZ shattered their port rudder in a violent nose-dive before racing started yesterday.

Racing proper is due to get underway in 10 days time with the start of the America's Cup qualifiers.

Watch: Team New Zealand's nosedive yesterday

The heart-stopping moment Emirates Team New Zealand plants their cat's nose underwater