To start with the AC75 is big - 75-feet long and 16-feet wide - but its also light which is crucial because the AC75 is designed to fly.

Ac75 keel. That will be a critical part of the AC75 and not all of it will be visible to the casual observer. Most notably the AC75 lacks a keel. Foil Cant Arms move under or outside the boat to provide the leverage it needs to stay upright.

Emirates Team New Zealand revealed its second generation AC75 to the world at its base in Aucklands Viaduct on Thursday. The leeward skin is more curved and therefore the leech is further forward. The physics of a foiling AC75 are as simple as they are complex but envision a large windsurfing board with towering sails.

Its also different rather than a keel a brand new concept keeps it standing. To start with the AC75 is big 75-feet long and 16-feet wide but its also light which is crucial because the AC75 is designed to fly. The rig height for the length of the AC75 is very short.

Its also different rather than a keel a. When you are in displacement mode because the boats dont have a fixed keel they are incredibly tender he explains. Christened Te Rehutai by Lady Margaret Tindall it is the boat that will be used to defend the 36th Americas Cup presented by Prada in just over 100 days time.

Hulls As explained in the article a year ago the hull of an AC75 in foiling mode should have zero lift zero heel and almost zero distance between the bottom of the hull and the water surface. Foil Cant Arms move under or outside the. There is no heavy keel to help keep it upright like a traditional sailboat.

The AC75 mainsail will have a different flying shape from the IACC monohulls sailed from 1992-2007 Americas Cups class and the hard wingsails used on the AC72 and AC50 in 2013 and 2017. When Luna Rossa heels its bottom is close to horizontal but its keel must induce some distortions in the water lines. The design uses the righting forces generated by the canting port and starboard foils for stability as well as to lift the boat out of the water at speed.