29 March 2018 - ETNZ and Luna Rossa, and their respective clubs, Royal New Zealand Yacht Squadron and Circolo della Vela Sicilia, today released the AC75 Class Rule for the 2021 America's Cup in Auckland.

ETNZ led the process, working with Luna Rossa, over four months. The rule includes one-design and supplied parts but leaves open wide areas for teams come up with their own designs for key elements of the yachts.

AC75 Rule Highlights

• The number of hulls, masts, rudders, foils and sails that can be built is limited
• The foil arms and the battery powered foil cant system will be supplied equipment
• The rotating mast will be one design and standing rigging will be supplied
• Double-skinned soft wing mainsail
• Eleven crew, all of whom must be human

That last point shows the rule writers have a sense of humor. Their intent was to limit the amount of automation the boat can use. Additionally, ETNZ wants design teams to do more work in simulation, reducing the need for real world testing. However, teams can still build test boats, as long as they ​are under 12 meters long.

The rule writers spent four months trying to write a fair rule with clear restrictions. Now they will shift to looking for loopholes to see what advantages they can find. Of course, the challengers will be looking for loopholes, too. ETNZ's head of design, Dan Bernasconi remarked, “Overnight we have to completely change our thinking, from trying to write a fair rule, to doing our best to design the fastest boat within the constraints of the rule. We have to stop thinking about what we intended the rule to mean, and start trying to pick it apart for what the words actually say - and see where there might be room to squeeze some advantage.”

The first AC75 yachts are allowed to be launched on 31 March 2019.