Te Aihe revels in some heavy conditions during testing in Auckland.

The vexed issue of the wind limits for the America's Cup has blown up big time with defenders Team New Zealand and the challengers at loggerheads and going to arbitration.

Under the Cup's protocol the wind range for the America's Cup match was meant to be signed off last Friday but the teams remain significantly apart on the upper limits for the new 75-foot foiling monohulls to be sailed at Auckland 2021.

Emirates Team New Zealand want 24 knots – the same that was in place for the 50-foot foiling catamarans at the last Cup in Bermuda. Their American and European opponents, headed by Challenger of Record Luna Rossa of Italy, want a 20 knots restriction in place.

EMIRATES TEAM NZ Team New Zealand's Te Aihe flying on its foils on Auckland's Waitemata Harbour. The revolutionary boat is now on its way to Italy.

They plan to use that 20 knots limit for their Prada Cup challenger series. The winner of that meets Team New Zealand in the match for the Auld Mug.

Team New Zealand label that "unrealistic for Auckland conditions" and the issue will now go to the Cup's Arbitration Panel for mediation, a process that could take as long as three months to settle. If Team New Zealand and the challengers can't be persuaded to come to terms, the panel will make a ruling.

READ MORE:

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* Team NZ capsize new boat

* Team NZ push wind limits

* Auckland gets Am Cup warmup regatta

"We don't know what their game is," a frustrated Team New Zealand legal and rules advisor Russell Green told Stuff.

"Whether they are trying to develop specialist equipment for the lower wind limit, we don't know. But we just think under 20 knots is ridiculous ... that is unrealistic for Auckland.

"We don't want a whole lot of races being cancelled in conditions that are normal in Auckland - solid 20 knots, that's what people expect to sail in here.

EMIRATES TEAM NZ Team New Zealand want the 2021 America's Cup sailed in conditions that are relevant to Auckland.

"This is a big deal but it's a bit like the tail wagging the horse at the moment ... you're being told 'we are only going to sail in under 20 knots in your town'."

There is less discrepancy at the lower end of the limits. Team New Zealand want 6.5 knots to be the minimum wind speed to start races while the challengers want 7 knots. The lower limit was 6 knots in Bermuda.

Ironically the issue comes public in a week where Team New Zealand capsized their new boat in around 10 knots on Auckland's Waitemata Harbour has they lost control coming out of a foiling turn while testing.

EMIRATES TEAM NZ Team New Zealand have proven the durability of the new America's Cup boat, quickly recovering from a capsize to continue testing.

But Team New Zealand have been comfortably sailing the boat well in excess of 20 knots during an initial three-month testing phase that is only discovering the potential of the new class.

"Our sailors say they find the AC75s significantly easier to sail in the upper wind range than the AC50 catamarans," Green said.

Team's New Zealand's quick recovery from the capsize and instant return to training was a big tick for the new boat in terms of durability.

EMIRATES TEAM NZ Te Aihe rolls over on its side during testing on Auckland's Waitemata Harbour.

Having this wind issue drag on will be costly in terms of arbitration expenses but more costly in time.

The teams have already started designing the second generation boats that will be sailed in Auckland for the Prada Cup challenger Series and the America's Cup match.

Obviously the wind limits will influence design.

EMIRATES TEAM NZ/TWITTER Peter Burling tells about the 'little mistake' that saw Te Aihe capsize in Auckland Harbour.

At the 2013 America's Cup in San Francisco, Team New Zealand found themselves victims of a late change in the upper wind limits.

They had designed a boat to withstand the rigours of the originally agreed 33 knot limit.

But when British sailor Andrew Simpson was killed in a high-speed training crash aboard Artemis Racing's 72-foot catamaran in the leadup, the wind upper limits were reduced to 23 knots for the business-end of the regatta which Oracle Team USA won with their remarkable comeback against the Kiwis.