Regatta: Copied? The America's Cup is threatened by an expensive legal dispute

The publication of the class rule for the cuppers of the current defence caused a stir in 2017. Monohulls foiling with double-sided swivelling outrigger arms had never been seen before. The system was allegedly designed by the New Zealanders and is used by all teams as a standardised system within narrow modification guidelines.

But now the Brazilian Manoel Chaves, designer and managing director of the shipyard MCP Yachts, which specialises in large aluminium yachts, is coming forward and asserting patent rights to the tilting keel system. He allegedly designed a similar system back in 2015 and applied for a patent, with the patent being published in 2017 before the new AC-75 rule was announced.

In fact, his invention, which he calls the Sailing Booster System (SBS), is strikingly similar in some details to the tilting keel system of the Cupper. Using an axle attached to the hull, boom arms can be lowered into the water with hydrofoils at the ends. The buoyancy can be regulated either by rotating the entire foil or by means of trim tabs on its aft edge. The teams also use trim tabs for the AC.

The SBS has already been tested on a cruising yacht and a video about it was published on YouTube in 2016 (see below). There is allegedly irrefutable evidence that the New Zealanders were aware of the system, as reported by the Brazilian magazine "Nautica", which first published about the dispute. It quotes Chaves: "We looked at where the access to our website came from to watch the video of our system and read the leaflets showing how everything worked. In a given period, most of the sessions came from internet users in New Zealand and Italy. In other words, they left traces."

Detailed explanation of the Sailing Booster System

Cup defender Emirates Team New Zealand rejected the accusations. The tilt keel system currently in use allegedly lacked key components of Chaves' design and was neither copied nor inspired by his ideas.

Chaves announced his intention to take legal action against the Cup organisers and also reserved the right to take action against any individual team using the tilting keel system.

The description of the Sail Booster System

The patent specification