The boat that wins will spend the least amount of time in the water. These things end up being more platforms than boats. The differing hull shapes here are interesting and probably represent each team's best thinking about how that platform should best handle both the air and the water. For instance, the Kiwi boat almost has air channels on the bottom of the hull.

The America's Cup has always been a design contest. The reason why America (the boat) won the race around the Isle of Wright and won the cup the first time around is because it was a new, radical design. Every cycle (for the most part) involves substantial innovation. Pretty soon you are literally flying around in boats.

I kind of compare the constant pushing of design to this:

If I had to reframe Barney's question, I think it would be "what is a boat?" Obviously the guy who builds the better boat will win a boat race. That doesn't detract from the need for seamanship. But there is such a thing as "a boat" and there is such a thing as "not a boat."

I think the sense that some people have looking at these is that they are getting close to being "not a boat."

a design contest. These boats push the design envelope where it has never been before. There have been foiling Moths for a long time, but they are small single handed dinghies. These are large boats with new foiling technology. Even back in the day of the 12 Meter boats there was very competitive design work going on that separated the boat speed of the contestants, all done in much secrecy. There is also a strong sailing skill component to these new boats. It takes a ton of sailing skill plus some new skills to just get them around the course. The world's best sailors are still sailing them.

I know it's total cheese, but I've always loved Wind. And it gets to your point. Design has been a huge part of this for a long time.

As a rule, a monohull boat will turn faster than a multi-hull boat. This is because the monohull is pivoting a single hull through the water while a multi-hull boat, say a catamaran, is turning extra hulls around a pivot point. Harder to get the nose around.

I say this as an old Laser and Hobie Cat sailor. The technology is so far beyond me now that I don't know if those rules apply. I would assume that they must in some fashion since the boats drop speed to make hard tack and the hulls drop back in the water, correct?

This is in very light air, which makes what these boats are doing very impressive. The video comes complete with cheesy music, so feel free to mute your speakers.

And training that goes into it.

But the technology is amazing.

We'll see if my kids continue to show interest in sailing, although I may probably have to work until I'm 90 if they do.