America's Cup: What Sir Ben Ainslie thinks about the Cup competitors' boats

In an interview with Mark Chisnell, in-house technology coordinator, yachting journalist and author, Sir Ben Ainslie spoke at length about the first designs of all four current Cup teams, which have now been undergoing tests for several months. The British team boss and skipper of Ineos Team UK is fascinated by the development of the first generation of yachts in the new futuristic AC75 class, describes the Italian design as "aggressive" and sees logical similarities between the New Zealand and Italian approach on the one hand and the American and his own team on the other.

The commonality of all four boats is not only obvious to Cup hunter Ainslie when looking at the top view: "It's really about making the hull look like one continuous piece - from the bow to the stern. As an end plate for the mainsail profile. This results in very, very significant aerodynamic advantages. All four teams have worked extremely hard in this direction. This has resulted in these trench-like cockpits on both sides of the boat. That is the constant that unites all the teams. Once you have this centre section and the inlets on both sides, the team is ideally accommodated in terms of aerodynamics and their wind resistance is reduced to a minimum."

On the design of the two "cockpits", Ainslie said: "There are definitely differences. Does your crew switch sides completely in the traditional way, or do you decide to split them up so that the sailors are firmly on one side? On the one hand, there are advantages in terms of the righting moment, on the other hand, there are advantages in terms of pure power efficiency if people don't switch. That's an exciting question to weigh up in this new class."

The 42-year-old said of the New Zealanders' AC75 yacht: "I think the Kiwi boat is pretty exciting. As is the Prada boat. They are quite similar conceptually. I was able to watch them quite early on in New Zealand. If you're a sailing fan and a fan of the technology involved, then you can't help but be fascinated by these boats, their performance and their potential. The Kiwis have this bulge under the hull to help the boat in its acceleration phase onto the foils. It's a pretty powerful boat. It's fair to say that. The Italians are also trying to incorporate this bulb into their concept. I think their boat is a bit more aggressive than the Kiwis. But once it's out of the water, it can be a pretty strong boat. It will be interesting to see how it performs at slow speed in displacement mode. But it's a very creative variation. I like a lot of the ideas on the Italian boat. They've really pushed the boundaries in terms of creativity. That's cool to see."

Ainslie compares the American design with his own - and he believes this is no coincidence: "We took a different approach in terms of the level of knowledge we had at the time we had to finalise the design. They are more like boats that have been created around the condition of being in displacement mode and using their hull to accelerate in that displacement mode and then rise up." According to Ainslie, there are "interesting ways of looking at" how the four ships move out of the water. The exceptional sailor also points out that the dynamics in which the new boats are sailed will play a part in defining which package will ultimately deliver the best performance.

The design phase for the second authorised Cup yacht has already begun for all four teams. "As you can imagine," says Ainslie, "this is a very crucial phase for the team. Once you've decided on a hull shape, that's it. Of course, you can still make modifications to the hull, but you can't fundamentally change it. So it's pretty crucial to get it right."

The complete podcast with Ainslie is here to hear.