America's Cup- Emirates Team NZ foiling on Waitemata Harbour - Images

by Richard Gladwell on 3 Sep 2012
Last Wednesday, after just her fourth day if sailing on the Hauraki Gulf, Emirates Team NZ were able to get their first AC72 sailing foil-borne on the Waitemata Harbour.

Sail-World has reviewed a sequence of 25 images which show the AC72 returning in a fresh breeze, rounding Rangitioto Light pursued by three chase boats.

She is sailing in a 15-20 breeze judging by the sea state outside Rangitoto Light. In the lee of Rangitoto Island, the seas are flat, as they clear the Island the seas remain flat, but of course the wind comes back up to its original strength.

The crew hoisted a furled gennaker as they passed Rangitoto Island

In the first attempt at foiling, New Zealand lifts her leeward hull briefly under jib alone, and with the windward foil apparently retracted.The boat is then stopped while some adjustments are carried out.

In later shots New Zealand is shown clearly foiling with the windward foil raised in compliance with America's Cup rules, which are designed to prevent the windward dagger board increasing righting moment. (http://noticeboard.americascup.com/wp-content/uploads/2011/08/ISAF-Racing-Rules-of-Sailing-AC-Edition-v-1.12.pdf!Click_here and see rule 47.3)

New Zealand then has her gennaker unfurled, and at the point the sail set she lifts clear of the water on both foils, begins a high speed sail down the Waitemata Harbour, past North Head at is entrance, and then gybes off Devonport.

She was fully foil-borne for a distance of over 1.5nm, and the photographer reports that the AC72 was stable i.e. not dropping out of foiling mode. While distances are a little hard to calculate accurately, the times on the images show that the run began with the breaking out the gennaker. It was fully extended (but not set) in an image taken 4 secs later. New Zealand was foiling in an image taken 17 secs afterwards and remained foiling until the last shot was taken 5mins 11 secs later, according to the metadata on the images.

The achievement would appear to give Emirates Team NZ a significant jump on other the other teams, only one of which is currently sailing. (Oracle Team USA sailed late last week for just two hours before damaging her starboard foil.)