The skirts are lifted

In the first part of our series following America's Cup unveiling day, designer Rob Humphreys looks at hull shapes

A long, long day in Valencia.... Last night Team Shosholoza and then the Italian +39 team jumped the gun on their competitors when they became the first to lift their skirts. These skirts have been shrouding the under carriage, topsides and occasionally the decks of the AC boats since the beginning of last season. At 0930 this morning (Sunday) the boats were unveiled and from now have to remain exposed for the remainder of the 32nd America's Cup competition.

For the unveiling, teams had to open the doors to their bases first for the press and then the general public over a period of three and half hours this morning. During this time personnel from the teams, members of the press and eventually the general public paced around from base to base taking in the new hardware - 18 new boats in total - with many design team personnel taking furious notes upon seeing their rivals' hardware up close for the first time. Thedailysail's team including yacht designers Rob and Tom Humphreys were among the fastidious note takers.

As we have written in the past, we are still impressed that despite the present America's Cup class now being 17 years old, there remains considerable development even over this last Cup cycle. As with most rules there are inevitably aspects where the optimum has been found and is now chosen by all. This is the case with displacement, for example, where all the boats are hitting the new 24 tonnes maximum (1 tonne lighter with the Version 5 of the AC class rule) and have near identical sail area. However in particular there still seems to be little agreement when it comes to hull shape, or bulb and keel foil shape. Much of this is down to each team's take on the weather - will it be more or less than the 14 knot average conditions? The bigger teams will be able to make a call from the long term forecast and will be able to carry out dramatic mode changes accordingly. Thus it should be pointed out that while the teams chose to unveil their equipment, it does not necessarily mean that this will be what they use during the Louis Vuitton Cup/America's Cup or even the Act 13 fleet racing due to start Tueday.

In the first article on what we learned from the unveiling we take a general look at the team's new boats while former GBR Challenge designer Rob Humphreys shares his thoughts on their hull shapes.

Generally Cup boats have the following dimensions:

LOA: 79ft (24m) - variation of <1.5m
LWL: 59ft (18m) - variation of <0.5m
Beam: 10ft 10in (3.3m) - variation of <0.4m
Draft: 13.44ft (4.1m)
Displacement: 24 tonnes
Typical upwind sail area: 350sqm
Typical downwind area: 720sqm

Alinghi - SUI91

Design: Rolf Vrolijk, Manolo Ruiz de Elvira, etc.



General: Considering that SUI 75 (the boat built for the 2003 Cup, but never sailed there) was pretty much up to speed with all the challenger's new generation boats last season, with only minor modifications such as the removal of her J-Lo (Alinghi's answer to Team New Zealand 'hula'), this bodes well for the performance of her new boats. The new boats appear to be like SUI 75 but with modified ends. All was going fine until SUI 91 was nailed 2-0 in some unofficial racing against Emirates TNZ's NZL 92 last week. Many believe this to have been an abheration.

Hull: This has a very straight rocker through the mid-body, from slightly forward of mid-foredeck to just forward of wheel. The stem profile shows a very soft knuckle, with more of a large radius leading to a fairly deep chest, achieving significant volume forward to allow some diminution of the mid-body volume for the 24 tonnes displacement. She has a fairly high prismatic form for up-range prowess, but also for fast light air sailing, perhaps consistent with the level of the team's self-confidence. In plan view the hull waterline is slightly convex running into the bow, suddenly ramping in towards the forward girth station. She has a foreshortened stem, minimising weight and windage in the ends, perhaps reflective of the Valencia sea state that is sometimes disproportionate to the wind. She has a fairly bluff local entry from her Dreadnought bow. Her shallow rocker also promotes increased fin span and aspect ratio, reducing induced drag. The run aft very clean and simple. In section shape, the boat is a soft U, not extreme and not unduly flat.


Alinghi - SUI100



Hull: Much as 91. The shape is perhaps a little more refined and not quite as aggressive. This shows confidence in their basic approach. She shows more general convexity in her waterlines than some other boats.


Emirates Team New Zealand - NZL 84

Design: Marcelino Botin, Clay Oliver, Nick Holroyd



General: While once upon a time there were three level pegging challengers, so Luna Rossa dropped away last year, while from a design perspective the new boats from Grant Dalton's Kiwi team are very much talk of the town. Sailing NZL 84 they were the only team to nail Alinghi in last year's championship.

Hull: Emirates Team New Zealand have a very interesting pair of boats with an overt aggressiveness masking a very sweet fundamental form. There is a very aggressive sheerline running flat forward then ramping significantly to the tip of the stem. This lowers the deck VCG, reduces windage and very marginally increases headsail area (headsail overlap is expressed as a vertical limit rather than as an LP measured normal to the forestay, as in most rating rules, meaning that a lower clew will produce more area for a given rated area).

The most noteworthy feature is the way the hull knuckles not just in forebody profile but in forward waterlines (right), with a significant increase in girth length abaft the forward girth station. Hard to explain in words, but at this knuckle position the hull volume is almost certainly greater for its longitudinal position than the other boats, creating the impression of a bigger boat and allowing the hull thereafter to be straight-entried and generally unprovocative, since the need to jam immersed volume into the other hull regions is much reduced. The hull section, for example, is gently U’d, with a soft and gently radiused bottom section, and no desperate transition from the Station 6/7 area to the afterbody turn of the bilge.

NZL 92



Hull: Rather like the relationship between the two Alinghi boats, 92 is conceptually close to NZL 84, but perhaps a fraction less pushed in detail. She may be slightly narrower than NZL 84. Again this displays a self-confident team that is following its own agenda, happy in its skin. Both boats are very straight-sided in section and apparently vertical-sided at BMax, through to the immersed canoe body. Overall beam very narrow, certainly among the narrowest. It could be that 92 is more refined in construction to allow more bulb weight, and perhaps one to be brought out when the racing gets more serious.

BMW Oracle USA 87

Design: Bruce Farr, Juan Kouyoumdjian and many many others...



General: BMW Oracle have the largest design team of all the campaigns, and have also been able to enlist the support of their giant car manufacturer sponsor. While they have been upstaged by the more radical looking Kiwi boats, the BMW Oracle offerings will certainly be on the pace. Near maximum of modification has been made to USA 87 so Larry Ellison's team have in effect built three new boats for this Cup.

Hull: This was extensively modified over the winter. Just under 50% area change in to her mid-sections. She is narrower now and characteristically similar to USA 98. She may have been modified to be closer to the planned configuration of 98. She appears slightly wider on deck forward than 98, but has a broadly similar stem profile to 98, but not quite as sweet. Her volume distribution aft a bit more forced than 98, with somewhat brutal diagonal delivery to transom turn of bilge. May be the outcome of the hull modification work.

Both boats are more heavily rockered than the Alinghi boats, and possibly have lower prismatic forms. The sheerline is fair and not as ramped as TNZ and others, and different from Oracle's 2003 generation boats.


BMW Oracle 98



Hull: Slightly softer bow knuckle than USA 87, perhaps better suited to Valencia conditions of relatively light air and disproportionate sea state. She has a slightly bluffer entry than 87. Probably one of the narrowest boats.


Luna Rossa - ITA 86 (right below)

Design: Bruce Nelson, Roberto Biscontini, Claudio Maletto



General: What on earth is going on at Luna Rossa? This is the third campaign for Patrizio Bertelli and once again the team appear to have speed issues with their new boats with what appears to have been a radical move to try and rectify this with their newest ITA 94. The size of Luna Rossa's design team is second only to BMW Oracle's and yet their boats seem to show no flair or great innovation - perhaps the result of too much design by committee and a design team this time lacking both Juan K and Doug Petersen. However slow the boat we know it will be well sailed by James Spithill and his team but some race pundits are wondering if Italy's no.1 team will even make the semi-finals.

Hull: Relatively gentle bow sections.

Luna Rossa - ITA 94 (left above)

Hull: Luna Rossa's second boat shows no significant development path from ITA 86, having departed greatly in concept from the earlier boat. This hints at a lack of confidence in their own development. ITA 94 looks a bit like a reaction to other boats, perhaps especially Emirates TNZ's ones, but the result is very aggressive with an apparently wide, shallow hull with this width carried forward right into the bow knuckle. The overall effect is somewhat reminiscent of a Star, with the forebody cut off and reinstated at a ramped up angle. It will be interesting to see how she performs in a left-over sea.

In consequence of all this, the rocker is shallower and the run-off flatter, possibly resulting in higher up-range speed than ITA 86. The choice of bulbs for unveiling day also indicated that the plan for ITA 86 to be the light air choice (with a short, low wetted area bulb, and ITA 94 with a relatively long, low VCG bulb.)


Mascalzone Latino-Capitalia Team - ITA 90 and ITA 99

Design: Harry Dunning



General: Vincenzo Onorato's team are back for their second attempt and this time they have gone two boat with design by American Harry Dunning (ex Farr, Reichel Pugh). In the unofficial racing this year they have shown themselves to be one of the biggest improvers. Their boats are notable for their 'icebreaker' or reverse 'Dreadnaught' bows.

Hull: Both boats are significantly knuckled and very bluff in their entry. They have a rounded entry rather than square, giving the impression of having somewhat convex forward waterlines. They have a ramped sheerline.

They could be pushing a lot of water aside in waves, which may be okay if the wind speed matches the sea state. Down range in waves or spectator wash they could be sticky. While the boats look similar forward, the after body of the newer boat develops into a very square turn of the bilge aft, compared to the older one, increasing heeled length.

Desafio Espanol - ESP 97 and ESP 88

Design: Reichel Pugh, Scott Graham



General: Although this team is new, Spain has a long history in the America's Cup and no shortage of competent sailors. Their two new boats will have benefitted from having Cup veteran Paul Cayard on board to help develop them. The boats appear to be up-range in terms of how they have been moded.

Hulls: Both boats are very similar, giving the appearance of sisterships with their relatively conventional knuckle bows and generally fair shape thereafter. Like Areva, they have been competently administered and viable in the also-ran category. Unextreme and unlikely to go home too early.


Victory Challenge - SWE 96

Design: Mani Frers, German Frers



General: In a discreet way one of the most innovative boats save for the Kiwi boats. However the team have suffered from a late launch (although the boat has been meticulously constructed) and the team has been scrambling to get her ready more than the other possible semi-finals contenders. Like Shosholoza the boat is possibly moded for a lower wind range.

Hull: She has fairly convex sections and waterlines, with a hint of a Dreadnought bow, in keeping with some other boats assembled in Valencia. She seems relatively beamy and with her fairly short bulb hints at manoeuvrability and match racing nimbleness rather than straightline speed per se.

Areva - FRA 93

Design: Bernard Nivelt, Herve Penfornis, Guillaume Verdier, Andrew Letche



General: Considering that they had the 2000 Cup NZL 60 to play with, the new French challenger appears unremarkable and almost old fashioned in appearance compared to the offerings from some of the bigger teams. She is expected to be an up-range boat.

Hull: Uncontentious concept, looks like a fairly safe development for a middle-order position. Knuckled bow and moderately ramped sheer, competently executed but somewhat innocent in style and inspiration by comparison with the more fancied teams.


Team Shosholoza - RSA 83

Design: Jason Ker



General: Originally Shosholoza were to build two new boats, but instead, for reasons of cost, it was felt most prudent instead to carry out a near maximum allowed modification to RSA 83. They are now shorter in terms of overall length but have a longer sailing length. She is only one of two boats (the other being CHN 95) with a bow sprit. The modifications are generally felt to have resulted in a significant improvement to her performance, helped by a relatively green sailing team who have been rapidly finding their feet.

Hull: This boat has had to be necessarily versatile. She was the first version 5 boat to be launched and was destined originally to be the first of two, and as such was not intended to carry the team’s ultimate hopes. She was subject to major re-build over the winter, with a nearly 50% (the maximum) surface area change carried out. The forebody was completely re-built from just forward of the mast, generating a finer entry more able to deal with the local sea-state and spectator chop. Almost totally knuckle-free - and about the only one in this respect. The other major change over the winter was a scalloped removal of the afterbody, creating a chine running aft and sending the after girth station forward by about 200mm. A consequent increase in aft girth penalty meant that this 200mm could not totally be reinvested in the forebody length, but it did allow the entry to be extended. She is probably still competitive as a result of these changes, particularly down-range.

The rig was moved forward over the winter by about 500mm to improve manoeuvrability.


Team Germany - GER 89

Design: Frederick Judel, Axel Mohnhaupt



General: Jesper Bank's first time German challenge only got to sail their new boat in anger in Feburary and have been struggling to get her worked up in time for this month's racing. Overall the design of their boat is unremarkable, perhaps 2003ish, like Prada after they modified at the last minute for the last Cup.

Hull: Fairly deep rockered and fairly convex waterlines. The knuckled bow looks to have a lot of overhang, a feature with which designers in Valencia have been generally fairly economic.


+39 Challenge - ITA 85

Design: Giovanni Ceccarelli



General: Strapped for cash, Iain Percy's team is bristling with Finn-sailing talent, but they have had precious little time to develop the boat and she is expected to be off the pace as a result.

Hull: Very narrow, certainly one of the narrowest, with significant knuckle forward extending to a fairly long overhang. Apparently limited in funding and they have been unable to progress any development work as far as the hull is concerned.


China Team - CHN 95

Design: Daniel Andrieu



General: China's first foray into the America's Cup has come about from their acquiring the Defi Areva team from 2003. Their boat was built by McConaghy's new facility in China but has an old keel and possibly the structure as well. They are believed to have recently had a major structural issue after they had been sailing in big waves.

Hull: Very aggressive, square-sectioned hull and knuckled bow that carries this flat section around and into the stem itself. It is rather like the new Luna Rossa hull in this respect. It has a fairly flat rocker, with much of the required displacement volume built into the sectional extremities. She has a Dreadnought bow with short bowsprit.

A lot more photos published on the following pages...

page 2 - stern quarter images
page 3 - bow images
page 4 - bow side profile images
page 5 - stern images
page 6 - stern side profile images