Team New Zealand's Cup of nations

Grant Dalton and Team New Zealand will reveal in September the protocol for the next America's Cup. Photo / Photosport

Team New Zealand will strengthen the nationality rules for the America's Cup, confirming the protocol will contain a "constructed in country" rule as well as a nationality requirement for competing crews.

But potential challengers will have to wait a couple more months to learn the full details of the next event, with Team New Zealand and Challenger of Record Luna Rossa releasing a statement yesterday announcing the protocol will be revealed in September.

Emirates Team New Zealand were able to confirm a couple of broader points, revealing the America's Cup match and the preceding challenger selection series will likely be held in Auckland in early 2021 during the New Zealand summer.

They also underlined their intentions to bring back a national element to the event.

"In recognition of the fundamental condition of the Deed of Gift that the Cup be preserved as a perpetual Challenge Cup for friendly competition between foreign countries, the Protocol will contain a 'constructed in country' requirement for competing yachts and a nationality requirement for competing crew members," the statement read.

The constructed in country rule - one of the underlying principles in the event's founding document - has relaxed significantly over the past 20 years. The 35th America's Cup in Bermuda required only a small 1.5m section of the bows be constructed in the country of the team's representative yacht club.

While farcical, the rule was of significant benefit to New Zealand's marine industry, with the bulk of Oracle Team USA's boats and componentry for the past two editions of the America's Cup being built at the team's Core Composites facility in Warkworth.

Core Composites were also able to leverage Oracle's close working arrangement with Team Japan over the last Cup cycle. But just how far-reaching the constructed-in-country rule will be is unclear.

Team New Zealand chief operating officer Kevin Shoebridge declined to comment on the details that have been drip-fed to date.

"We can't say any more that what has been published. We just wanted interested parties to know we are on track with our protocol announcement for September," he said.

Yesterday's statement contained no reference to the most burning question for the next regatta - what class of yacht will be used?

Luna Rossa boss Patrizio Bertelli is said to strongly favour a return to monohulls, but the feeling among many of the current America's Cup sailors is that the "Formula One on water" style of racing created by Oracle Team USA bosses Russell Coutts and Larry Ellison with the move to foiling multihulls should be preserved.

Given Team NZ won the America's Cup in foiling catamarans, it would seem counterproductive to throw away the past three years' of research and development.

The issue of what class of yacht will be used is expected to be a determining factor for many potential challengers.