The AC75 design rule is a so-called box rule which sets some key parameters such as hull length and overall length with bowsprit 75ft hence the name AC75.

Ac75 vmg. Given the upwind VMG is about 15kts - you can work out how that translates into boat speed. Additionally racing is controlled by time limits of 12 minutes for the first leg based on a VMG of 6kts for the 12nm leg and a limit of 45 minutes for the whole race. We define velocity made good on course and velocity made good upwind.

ON THE FIRST TRY for the ac75 compared to years of experience for slingers on the 50s. Now the view seems to be accepted that the hull is just an endplate between the rig and the water - which explains the unusual for a regular monohull yacht design treatments of the deck and cockpit design of which Emirates Team New Zealand is probably the most extreme example. Upwind the AC75 will need to build speed by coming off its optimal VMG upwind course for some time and may have to sail a reaching course to some degree Eventually speed will build and from a rig point of view while reaching sheets will be eased a little and come back on as the boat pops up.

When the AC75s first appeared back in September 2019 the fan focus was all on hull shape. The AC75 Americas Cup 75 is a racing yacht used in the 2021 Americas Cup match and planned to be used for the 37th Americas Cup and 38th Americas Cup matches. Maybe its just the changing wind direction that it cant make changes quick enough but its really annoying.

Heres a quick and easy way to determine the right downwind angle using a few simple tools. You can post now and register later. Good comparison of how the boats stack up.

Link to post Share on other sites. Its a significant change. AC75 with rounder longer tacks that the F50 which gives better vmg.

Stick a fork in it this comparison is done. The second point the hull must have a function of an airplane wing at low speed and near the land. The 23 m 75 ft monohulls featured wing-like sailing hydrofoils mounted under the hull a soft wingsail and no keel.