Gone are the days of one-boat racing. Today, the America's Cup will see four 72-foot AC72 catamarans on San Francisco Bay, with two official races planned and some pre-final racing by Oracle Team USA's two yachts.
That's if the wind limits do not interfere - and there are fears the second race between Luna Rossa and Emirates Team New Zealand may have to be postponed.
The Louis Vuitton finals begin at 8.10am NZT, with race two of the best-of-13 series due at 9.10 am. Before that, Oracle's two boats will race against each other on the same course.
This is a new occurrence - not because OTUSA have two boats on the race course but because this is the first time they will release telemetry data which reveals (to expert analysts) how fast they are going; data which is available to other teams for the first time.
However, while the Oracle yachts will race, there are doubts about the second Louis Vuitton race going ahead. Wind limits for the Louis Vuitton are set at 21 knots. Regatta director Iain Murray said today that, corrected for an outgoing tide, the wind limits for the second race would be only 19.4 knots.