Americas Cup AC75 fully foiling mono unveiled ...

[Polux]

I don't understand your answer. For a boat to be able to self right itself a lot of RM is needed.

The new 75 monohull, ballast an all, it will be lighter than the AC 73 catamaran that was used in 2013 and it will have a 5.3m beam and a righting moment of 45T/m. Probably that is not the max RM but the usable one while sailing. That is the one that is limited on box rules

That is not a small righting moment but a big one.

For comparative purposes the max useful RM defined by the IMOCA (Open 60's) box rule is 25.5 Tons-meter at 25° of heel.

Guillaume Verdier, that is the man behind that concept (see the post on my blog about it), describes how the boat works:

"It is a boat that has two modes: classic, when it sails with the ballested foils under the boat, and as it accelerates, the dynamic mode takes over, the foils can lift the boat that sails over the foil under the wind while the other provide the RM and stability that allows to lift the boat out of the water . For the foils, there was a big design work with Bobby Kleinschmidt and Steve Coolie, the idea was to have a boat that has an initial stability, it will not be a 75-foot moth. "

[donradcliffe]

The will be very expensive to build and to sail. I predict it will be abandoned before the next cup.

[Polux]

Originally Posted by donradcliffe

The will be very expensive to build and to sail. I predict it will be abandoned before the next cup.

Price was never a problem on the America's cup. What can happen is that the number of boats on contest are less.

Do you remember the incredible first 90ft multihulls? Difficult to have more expensive boats than those.

The America's cup is mostly a competition on boat design and the objective is to push the sailing boundaries.

I would say that regarding that the last editions were much better than the previous ones when they were raced on monohulls that were not even the fastest monohull around:very fast upwind but slow downwind.