Team New Zealand have picked up their first point of the Louis Vuitton finals but it came at a hefty price as the Kiwis suffered serious gear damage, losing two men overboard in the process, mid-way through a race that was effectively over just seconds in.

Team NZ were left to once again sail around the course by themselves after Luna Rossa were forced to withdraw from the race early on with damage to their starboard daggerboard.

Read Paul Lewis' column on 'The Beast' emerging in San Fransisco.

But there was further drama to come after a disastrous mark rounding from Team NZ saw two men thrown overboard and serious damage to the fairing.

Providing a stark reminder of just how on-the-edge the high-powered racing machines are, Aotearoa went into a terrifying nosedive as it rounded the fourth mark, burying the hulls up to the main crossbeam, which saw their boatspeed drop from 40.7 knots to 13 in the space of a second.

The sudden deceleration and torrent of water on board sent the crew flying, with Rob Waddell and Chris Ward sent overboard.

Both were unharmed in the fall and were quickly retrieved by the chase boat.

Despite the torn carbon fibre on the aft side of the main crossbeam flapping in the wind, Team NZ were able to limp around the race course, completing race with just nine men on board. But the shore crew have a long night in the shed ahead of them and an expensive repair bill.

Team NZ skipper Dean Barker, who was thrown violently against the wheel as the boat went into a nosedive, played down the severity of the incident.

"It's just this sort of racing. These boats are incredibly powerful, you can see how the speed rockets up as you make the turn. We had good pressure - and we were always going to make quite an increase. I am sure there were some things we could have done better," said Barker following the race.

"When we got to the top end, it wasn't that extreme, but if you don't get everything right, you make it tough [for yourself]. We'll have a good look at our systems and we'll be ready for tomorrow."

Knowing Luna Rossa would be unable to compete in the second race with their damaged board, Team NZ were still keen for race two to go ahead despite their scare in race one. But with the wind picking up later in the afternoon exceeding the wind limits, the race committee called the second race off.

The Italians struck trouble pre-race when they found a problem with their starboard daggerboard. Fortunately for Luna Rossa, the start of the race was delayed slightly due to high winds, allowing members of the support crew to frantically effect repairs.

After some handy work with a hacksaw and glue gun, they managed to get to the startline just in time.

But it was clear early on they still had a problem, with helmsman Chris Draper missing a prime opportunity to hook Dean Barker in the pre-start, which would have handed the Italians control of the start.

After a fairly even start, Team NZ accelerated to the first mark and rounded just two seconds ahead before the Italians slowed dramatically as their daggerboard bobbed up and down in the water.

It set the tone for a dramatic race.

Prior to the finals series getting underway, Oracle Team USA had their two AC72s on the racecourse for some in-house racing. Skipper Jimmy Spithill and helmsman Ben Ainslie guided the two black cats around the race course, putting on a show for fans that had turned up early.

In a change of tack, Oracle agreed to supply all their telemetry data from today's in-house racing. Team New Zealand lost a jury ruling earlier this month over the one-way flow of information.

Oracle have had access to all the challengers' performance data during the Louis Vuitton Cup, and Team New Zealand argued during the defender access period to the race course the US should also have to disclose their data.

The jury disagreed, ruling Oracle are not obligated to reveal their numbers, but the defenders opted to release their performance data from today's practice racing anyway.