The controversial penalty which allowed Team New Zealand to snatch victory away from Artemis today was based on a pre-agreement among the teams about how mark roundings should be policed in the America's Cup.
The rule came about as a result of a few incidents on the America's Cup World Series circuit last year, including one involving Emirates Team New Zealand in Japan. Given the closing speeds involved when you have two high-powered, but highly skittish, foiling catamarans out on the race course, it was decided in the interests of safety, the margins at mark roundings needed to be extended.
The amount of room the right of way boat needs to be given is not defined, it is more about the ability of the gybing boat to perform the manoeuvre safely, rather than a crash gybe.
The boats can quickly get out on control if they are forced into sudden manoeuvres, as was the case in Sunday's opening day of action when Ben Ainslie Racing collided with Team Japan.
In today's incident, Artemis came flying into the mark on the port side, while Team NZ had the starboard advantage. With the Swedish boat bearing down on them quickly, helmsman Peter Burling took evasive action, causing the boat to dig its bows in before rearing up again and coming to a complete halt.
