America's Cup: Team NZ in for frustrating day with light winds likely to disrupt racing

Emirates Team New Zealand are scheduled to race Team BAR today. Photo / Chris Cameron

Team New Zealand could be in for a long, frustrating day on the water on day five of the America's Cup qualifiers, with light winds threatening to disrupt racing.

The forecast from Bermuda Weather does not look promising, with a wind strength of 2-5 knots predicted during the racing window. To get racing under way, a minimum average of six knots is required.

However, regatta director Iain Murray said the forecast models coming from each of the syndicate's weather teams are a little more optimistic.

"I think there is some hope that the breeze will get around to the east and we might have enough wind," said Murray.

Racing will not be called off beforehand - the teams will all head out on to the water at the scheduled time, and bob around out there for the entire racing window if need be.

To get a race underway they will need to have an average wind speed of 6 knots during the five minute window between 8 minutes out from the scheduled start, and 3 minutes from the start. The average is measured over 30 second intervals.

If at any point in that five minutes the average wind speed dips below 6 knots, the race committee will have to re-set and try again. Murray said during the practice racing window last month, there was one day when officials had 25 attempts to get a race under way.

Here's @americascup regatta director Iain Murray's highly qualified assessment of whether we'll get any racing in today ... pic.twitter.com/ZOEy3vVBnT

— Dana Johannsen (@djohannsenNZ) May 31, 2017

Asked what racing in six knots might look like, Murray responded:

"Most of the race yachts will actually foil across the first [reach]. Then the trouble starts, you have to go to the bottom mark. The boats can reach okay, they will go upwind okay, but they have a lot of difficulty going downwind," he said.

"My analogy is they're like a blunt saw trying to carve their way through.

"Our instructions to the guest chasers and people on the course this morning is just be aware that when these boats gybe, they will probably turn 180 degrees and come straight back at you as they try to build apparent wind speed."

The time limit to complete each race is 25 minutes, but unlike in San Francisco four years ago, race management have the ability to shorten the course during the race if it is looking like the boats will exceed that limit. There are several ways in which they can do this: they can shorten the length of each leg, or they can cut out legs entirely.

The only requirement is that the boats get to the first leeward gate in 10 minutes, and a minimum of four legs are completed. A full race is seven legs.

Murray said he has the ability to extend the racing window out by an hour to 5pm local time (8am NZT) in order to get some racing in.