In contrast to the usual razzamatazz of a busy press conference hosted in the next Cup location (I wish), the announcement of the new class for the next America’s Cup has been a quiet online affair and yet represents a huge change.

Out goes the AC62 and in comes a 48ft wing masted foiling cat as the boat that will be raced in the 35^th America’s Cup in 2017 in Bermuda.

In the last 24 hours the new class rule has been published and sets out the detail of the new boat.

But while the change required a majority vote, and as yet no team has said it is pulling out, not everyone is entirely happy. Since the vote no one has heard from Luna Rossa and the Kiwis, while they have accepted the new design, are believed to be less happy about the prospect of not having a regatta in Auckland as part of the challenger series in 2017. (Given how Team New Zealand’s funding from the Government depends on hosting an event and the team’s view that they have an arrangement with the organisers, this looks likely to be a debate that could rumble on for some time.)

So what of the AC48, why the big change and what sparked such a significant move midway through the next Cup cycle?

Word has it that the initial idea for a smaller boat came from Larry Ellison himself who, having seen what his team were doing with their development cats, asked why this couldn’t be used in the next Cup. The message got passed on, the question asked, the debate fired up and a vote has seen the change implemented – arguably the fastest major change the Cup has seen in many years.

But why is this boat so more attractive than a towering 62 footer?

The answer lies in the rapid and to a large extend unexpected, development of the test boats.

Both Oracle and Artemis have been on the water with their lighter, wider, more powerful and more sophisticated 45 footers, ‘turbos’ as they are calling them. The results have surprised all of them.

“I think all of the teams who have been sailing the so-called AC45 ‘turbo’ boats over the past few months have been surprised by the performance they’ve seen, which is partly what inspired this idea of a new, smaller class,” said Oracle’s tactician Tom Slingsby. “In our boat we were doing roughly the same speed as the 72 when the breeze was up and we were maybe a little faster than the 72 in lighter winds.”

What does that mean?

“We hit close to 46 knots of speed in 16 knots of wind,” he continued. “But I think there is a lot more to be gained still.”

Now we’re talking.

When teams started looking into the development for the next America’s Cup, few if anyone guessed that the learning curve would still be so steep with so much to be gained. Aside from the greater width and therefore greater righting moment and power of the turboed 45s, the development of slicker foils and more sophisticated control systems for them has allowed teams to push way beyond where they expected.

Given the rapid development along with the constant underlying pressure to reduce the cost of Cup campaigns, there seemed little reason not to change.

Many of the big teams that had already invested time and money into the 62s openly admit that a great deal of the lessons they have learned so far are applicable to any sized foiling cat.

But to get a better grasp of just how rapid this development has been, take a look back at the rate at which Cup boat speeds have increased over the years. For over a century Cup boats have pushed water around the course at a little either side of 10 knots. In the last fifteen speeds have almost quadrupled.

Even in just seven years the picture has changed dramatically. In 2010 the giant cat and the tri were at the very leading edge, we all thought they looked pretty cool and impressive, now they look rather slow and unnecessarily big.

On that point, the time it took for the behemoths to manoeuvre ruled out close quarters, fast paced tactics. Smaller, more nimble 48-footers should up the ante in this area, too.

Yet one of the clever aspects of the new rule is that not everything has changed. Far from it. Some areas such as the hulls, which now play a small part in the overall performance of the boat as they are rarely in the water, are tightly controlled under the rules. So too is the wing, which is simply a scaled down version of the one that was allowed under the AC62 class rules.

“The wing rule is exactly the same as it was for the 62, (albeit scaled down), with the geometry defined, but the control systems completely open,” said Slingsby. “Again, I think you’ll see a lot of different ideas from the teams here. There are gains to be made in ease of use, how the boat manoeuvres, how the wing pops through on tacks and gybes. If we start considering foil-tacking for example, this area becomes so important. Having excellent control systems for the wing and appendages is critical.”

The rules governing control systems on the other hand a far more open although the boats will remain manually driven with the use of stored energy banned. Windage is another area that will play a big part in the overall performance.

“Aerodynamics is also wide open for this boat,” says Slingsby. “When you’re going upwind at 30 knots with 20 knots of wind over the deck, that’s a 50 knot headwind, so you can imagine what a difference aerodynamics will make. I think we’ll see different ideas here too.

“Having systems that allow you to push the envelope to go to places we’ve never been before – foil-tacking a catamaran – that’s absolutely huge.”

So when will we see the new boats?

Not until 2017. Until then teams will continue to develop their trial horses. The AC World Series events will continue to use the former AC45s up on foils, but the new boats will look very different. Most noticeably they will have wheels rather than tillers and have cockpits like the AC72s.

And will new teams join as a result of the new class? Maybe.

At present the most likely to join will be a Japanese team although this is yet to be confirmed. There is also talk of another Asian team being discussed, but again few details to back this up.

Whether the new rules inspire any others to join remains to be seen. Late entries are permissible subject to being accepted by the Golden Gate Yacht Club (GGYC) but under the AC35 Protocol any latecomer would sign up to the same terms as the current Challengers and would therefore have to pay the same amounts as the other teams starting with $2million before the first AC World Series event.