They may look similar at a distance, but close up no two America’s Cup yachts have got the same sail plan.

BYM News’ Aldous Grenville-Crowther went along to hear what the men behind the sails had to say.

Mickey Ickert, principal sail designer, BMW Oracle Racing, on jumperless rigs.

We look at all developments from the bottom to the top of rig and we’ve had this concept looked at a few times. Ours came out a few weeks after Alinghi’s, but that timing was coincidental; the teams have all got programs & they are a lot less influenced than you might think by what others do. It’s all a question of your design technology and the ability of your engineering unit to follow through. This mast with no jumpers has big implications right across the board for sailing boats, but I make no pretence that we are anywhere except on the bottom of the learning curve. We’ll learn a lot more about it just by setting it up and using it out there; we want to get on with it and learn as much as we can and these regattas are a good opportunity.

Guido Cavalizzi, sail designer, Luna Rossa Challenge, on large roach headsails.

This is one of the most important changes in the rule and, for sure, it’s important to have the bigger sail. It’s also important, though, that the crew can manoeuvre the boat as they wish, so it’s hard to know how much to push some of these concepts. What is important, in my opinion, is to develop things together with the crew. If they feel they are part of the input that is better for the boat, because they feel they understand more what they are using and, in turn, they can then contribute more to telling me what they wish to have different, which is part of the development path we are all following.

Juan Garay, sail designer, +39 Challenge, on inflatable battens.

There are many different approaches. Most of the teams are developing their own inflatables and using a combination of standard battens and inflatables. Now there are companies coming out with a product ‘off the shelf’, which is a really good thing for us smaller teams.

Burns Fellows, head of sail program, Emirates Team New Zealand, on whether coloured spinnakers are compromised.

It’s interesting, if you look back to last year, many spinnakers broke during the Louis Vuitton Acts. BMW Oracle Racing had one go here in Valencia, Alinghi had one go in Malmo and Luna Rossa as well. So, based on last year you could have formed a conspiracy theory on white spinnakers, since we only had one minor episode last year.

When we chose the red spinnakers, for our main sponsor Emirates, the first thing we did was to check all the material properties, for stretch and so on and basically there is no difference. We wouldn’t be using the red spinnakers if we were not comfortable with them. We obviously have had a failure, but we expect to get over it.

Laurent Delage, sail designer, Victory Challenge, on why staysails sails are suddenly so popular.

They were developed at the last America’s Cup and definitely bring something to the boat; more stability, more speed, more capacity to sail lower, so they are an important part of our package on Victory Challenge. We are working mainly on trying to create a package for the new boat and this is a very important part of it.

In the America’s Cup, there is a lot of detail in the sail development, you see a lot of things that were invented a long time ago come back. It is a big loop and things are improving and going back and forth.

Sandro Benigni, sail designer, Desofio Espanol 2007, on carrying forward sail developments to a new boat.

Every boat has a quite a different aero package, because clearly the boat is different, and I don’t think any boat has the same sail shapes, or aero package, as the previous one. Clearly though, most of the development we have made on sails will be going to over to the new boat and we will make adjustments, when we see how the new hull will sail and operate with them.

Matthew Woolley, sail loft manager, Shosholoza, on what happens after sailing

Depending on which ones have been up they may need work, re-cuts. Spinnakers go into the drying area, after being washed. It’s a big job to unpack every headsail that’s been out on the boat that day, but we start to check over any sail that’s been up that day, then go up to the design office for a let down - nine or ten o’clock at night - and then the night shift works.

It’s anything from a six to twelve hour job for the guys at night, basically crawling over every sail, checking everything from top to bottom, to make sure it’s all in good shape for the next day.”

Bruno Dubois, sail manager, Areva Challenge, on how long sails last.

You would be shocked if I told you how long they last, so I’ll leave that to others. We build about three sails for testing and training, for every one for racing.

Mickey Ickert, principal sail designer, BMW Oracle Racing, on how long sails last.

It really does depend on how much you sail, at the end of the day. The bigger teams manage more sailing, which makes higher usage. If you sail 360 days a year you are going to use a lot more sails than somebody who is sailing 150 days, so you can’t really compare numbers.

Giovanni Cassinari Mascalzone Latino-Capitalia, on carrying forward sail developments to a new boat.

We know the new boat will be much better than the one we are using now. So far we have had to sail the boat with the old version mast, but the boat will be so much better with a new mast and that’s what we’re focussing our sail design program on.

Jean-Pierre Baudet, sail designer, United Internet Team Germany, on the ‘trickle-down effect’ of design innovations

I think you will see some benefit for the larger sailing world, even though these boats have very specific needs and characteristics. Here we have 12 boats and their designers are all trying to solve the same problems, whether it be with the width of the head of the mainsail or how to control the vertical camber on the jib, or how to make the kites the most stable. You have 12 guys, with many more people behind them, trying to find solutions and this