America's Cup: Emirates Team NZ - Up, up and away on foils

Emirates Team NZ’s AC72 under controlled flight - with only one rudder in the water as she heads up the Waitemata harbour - September 14, 2012

Emirates Team New Zealand swung by a Friday evening race over three weeks ago after their seventh on the water session. Sail-World's camera caught the action as the AC72 reached down the back of Rangitoto and then gybed before getting up on her foils again for another run down the harbour.

Here we present an image analysis showing what foiling in an AC72 is all about - showing some of the points of technical interest, and track the process of foiling from start to full flight on one daggerboard and a single rudder.

IMG 8302 Flying down the back of Rangitoto. Note gennaker is fully sheeted and set. Goosewinged yacht indicates wind direction. Sea state indicates 12-14kt breeze. Boat speed estimated at 30kts - Emirates Team NZ September 14, 2012


IMG 8309 - Emirates Team NZ has just gybed, gennaker has been furled and is being sheeted.


IMG 8337 - Emirates Team NZ sheets gennaker, but is powering up with it only half set as the apparent wind moves forward. Both foils are down


IMG 8346 - Emirates Team NZ turns downwind as leeward hull starts climbing, still building speed rapidly despite gennaker being seriously backwinded and not fully sheeted. Both foils are still down


IMG 8348 - Emirates Team NZ’s leeward hull starts to lift clear of the water, gennaker not filling, both foils are still down


IMG 8361 - Emirates Team NZ fully lifted on both foils, note the slimness of the hulls in this bow on shot. gennaker is still not fully drawing as apparent wind is still moving ahead.


IMG 8377 - Emirates Team NZ’s windward foil is lifted clear of the water


IMG 8385 - Emirates Team NZ turns downwind and is close to paralleling the course of the keelboat sailing goosewinged and running dead downwind. Windward foil is retracted. Windward rudder has lifted clear of the water, but balance is maintained.


IMG 8400 - Emirates Team NZ settles down, Windward rudder back in water, but gennaker still not fully setting.


IMG 8417 - Emirates Team NZ at warp speed. Gennaker now drawing fully as it was in the image taken before the gybe (IMG 8302). ETNZ is still running near dead downwind, evidenced by the angle of the catamaran in the background, which is reaching across the breeze.


Emirates Team New Zealand at full pace