Please select your home edition
Edition
Marine Resource 2016

Foiling in just 8 knots- the new Mk2 GC32

by The Great Cup on 14 May 2014
Up on foils, the GC32 achieves incredible speeds, stably. Sander van der Borch Photography www.sandervanderborch.com
Foiling in just 8 knots - After six months of intense R&D, the GC32 has been fitted with its Mk2 set of foils and has now joined the twin-hulled elite - like the AC72s of the last America’s Cup - in becoming a fully foiling, airborne, racing catamaran.

The Martin Fischer design, in production at Premier Composite Technologies in Dubai, had its first sailing season last year. Then it was fitted with L-shaped rudders and double-S shaped main lifting foils, which, above 15 knots, typically held 80% of the boat’s displacement. New state of the art T-shaped rudders and J-shaped main lifting foils now enable the GC32 to sail clear of the water.

With its new foils fitted, the GC32 has been undergoing sea trials in La Grande Motte in the south of France with spectacular results. So far the boat has proved able to foil in as little as eight knots of wind and impressively can do so not only downwind, but upwind too – something that was rarely seen on the AC72s, until Oracle Team USA mastered it during the 34th America’s Cup itself. But most impressive is that the GC32 can foil stably, with almost no hobby horsing or porpoising.

Also, while the AC72 crews had to bust their guts as they wrestled their powerful craft around the race course - principally because of the constant grinding necessary to keep pressure in the hydraulics operating the wingsail and the foils - on the GC32 there is nothing like the same athletic requirement: there are no hydraulics and the rig uses conventional soft sails.



The helm on the GC32 has proved to be well balanced and while it takes some minimal liaison between helmsman and mainsail trimmer to get up on the foils, to ‘get in the groove’ and then to remain there, the boat is surprisingly easy to sail even for a crew of average ability. In short, you don’t need Olympic medals or to have spent decades racing catamarans to get foiling in the GC32.

Despite being well-mannered, the GC32 still delivers unprecedented performance. After just two weeks of sailing, the boat has been foiling upwind at more than 20 knots in less than 10 knots of breeze and recorded 27 knots downwind in the same conditions. On one subsequent run the boat averaged 30 knots over four minutes. And these numbers are just from the preliminary trials - speeds approaching those of ORMA 60 trimarans a decade ago, all achieved under full main and jib alone, without using the gennaker, from a boat almost half the length, that can be demounted and trailered home after racing!

How is this possible?

The key to the GC32’s combined high performance and foiling stability, lies in its latest generation foils. In profile these resemble the foils used on the AC72s which form a V-shape when lowered and then incline inwards when raised, turning the ‘V’ into a discreet ‘L’ shape. However the significant difference with the GC32’s foils compared to the AC72s’ - which were developed for San Francisco’s strong conditions – is that the former are substantially larger relative to boat size. In fact the 1.6m long horizontal lifting part of the GC32’s foils is the same length as some of the smallest foils Cup teams were developing for their AC72s.

But this is where the similarity ends. The GC32 foils are substantially higher aspect (ie their chord and thickness is much less for their length). This approach maximises the foils’ vital lift to drag ratio and this, combined with their span, is what enables them to operate so effectively in low wind strengths.

In terms of their lineage, the foils are the latest iteration of those developed for Franck Cammas’ International C-Class Catamaran Championship winner Groupama C (for which Martin Fischer was part of the design team) and the Fischer-designed Flying Phantom F18, originally the Groupama team’s test platform for its C-Class catamaran.

Further refinement of the GC32 foil’s design has since taken place in conjunction with the GC32’s project manager, Andrew Macpherson, former Alinghi engineer Brett Ellis and Laurent Tournier of the foils’ builder, Heol Composites. The result is foils very close to the limit of what it is currently possible to build in composites.

Heave stability

The stability of the ride when foiling is partly due to the size of the foils, but also their design. The V-shape the main lifting foils form when fully lowered encourages them to auto-stabilise: The faster the boat goes, the more the foil lifts out of the water and the less lift it provides. Conversely as boat speed lowers, so more of the foil drops into the water, exposing a greater surface of foil, which provides more lift. The end result is good ‘heave stability’ and minimal porpoising.

The design of the latest foils also addresses more subtle aspects such as the effect leeway has on them and how their bending characteristics affect performance.

'It has been a long winter because making it fly was pretty ambitious,' admits Laurent Lenne, the Amsterdam-based French entrepreneur, who is creator and owner of the GC32 class. 'We want a state of the art product and if everyone is flying in the America’s Cup, then we had to do that too.


'The first time we sailed the boat was very, very tense and it was a huge relief when we flew straight away. But these are fifth or sixth generation foils, following on from all the work done with Groupama and the Flying Phantom, so we knew we weren’t starting from scratch. To nail it from day one – we were very happy with that.

'We wanted to have a very stable boat allowing people to fly very easily and even when you are doing 27 knots, it is a picnic on board. In terms of how the boat behaves, it is very stable, but it is still very, very fast.'

VIP guests

Helping work up the GC32 with her new foils has been former Luna Rossa crewman, Paul Campbell-James, currently helming the Gazprom Team Russia catamaran on the Extreme Sailing Series, where he is a two-time series winner.

'The most amazing thing is that we’ve been fully foiling upwind and downwind in 8-10 knots of breeze - it is amazingly fast and really easy,' he says. 'The tips on the foils are huge and so there is massive amounts of lift available at all times, which is pretty useful. It possibly limits top speed when it is windier, but in order to be able to foil all the way around the track in 8-10 knots of breeze is pretty unbelievable.


'The boat is very stiff, which is good for foiling and the foil design seems very good. It was all just amazingly easy.'
Oracle Team USA coach, Philippe Presti was also down for the trials.

'I think they did a good job,' says Presti of the GC32 team’s efforts. 'I know the time it took to make, for example, the AC45 foil properly and these guys got it right almost on the first shot.'

Presti was present for two days of the trials, the first in stronger conditions when the GC32 averaged 32.5 knots for one five second burst. The second day was lighter and in 14 knots she was making 18-19 knots upwind at around 50deg.

'It is early days for these boats. By just trimming the sails and the foil you would improve the performance by quite a lot. I think the tool is great. Off the shelf, it is pretty impressive.'

According to Presti the take-off boat speed of Oracle Team USA’s AC72 was 23 knots – this compares with around 15-16 knots for the GC32.

In terms of wind strength... 'I would say you need 12 knots to foil upwind, but you can definitely foil upwind from 10-12 knots to the top of the range. Downwind, you can foil pretty low - it depends if you are sailing with the big genniker, but you can foil in 7-8 Great Cup

Zhik Dinghy 660x82Southern Spars - 100upffront 660x82

Related Articles

Oman Air stay top of Extreme Sailing Series table with podium place
Oman Air stayed top of the overall leaderboard after posting a third place in Act six and shifted focus to the next Act. Oman Air stayed top of the overall leaderboard after posting a third place in Act six in Madeira and immediately shifted their focus to the next Act in Lisbon, Portugal, in two weeks.
Posted today at 7:00 pm
Olympic Gold medalist and Volvo Ocean Race winner up for WS Board
Torben Grael (BRA) is amongst the 15 nominations for one of seven places on the Board of Directors of World Sailing Torben Grael (BRA) is amongst the 15 nominations for one of seven places on the Board of Directors of World Sailing in November. The five times Olympic medalist, Volvo Ocean Race winner and several times America's Cup competitor will bring a much needed sailing edge to the Board of World Sailing if he can navigate the politics of the controlling body of the sport.
Posted today at 6:03 pm
Panerai Classic Yachts Challenge - Images from Régates Royales
The final round of the Panerai Classic Yachts Challenge is underway at Cannes in the 38th Régates Royales. The final round of the Panerai Classic Yachts Challenge is underway at Cannes in the 38th Régates Royales with classic yachts and Dragons. Eugenia Bakunova of mainsail.ru was on the water at Cannes and provided this gallery of images from the penultimate day of the regatta.
Posted today at 11:12 am
Panerai Classic Yachts Challenge - More images from Régates Royales
Second gallery from the final round of the Panerai Classic Yachts Challenge at Cannes The 38th Régates Royales, the final round of the Panerai Classic Yachts Challenge is underway at Cannes. Eugenia Bakunova of mainsail.ru was on the water at Cannes and provided this second gallery of images from the penultimate day.
Posted today at 10:56 am
World Sailing - Henderson sets out foundations of his President bid
Paul Henderson is standing for another term as President to get some significant and vital issues facing Sailing address Paul Henderson is standing for another term as President to get some significant and vital issues facing Sailing addressed by sailors with their input both individually and via their International Class Associations. Henderson sets out below what he believes will be the foundations of his next Presidency.
Posted today at 10:55 am
World Sailing President nominated by 45 Member National Associations
Incumbent World Sailing President, Carlo Croce (ITA) has welcomed nominations from 45 Member National Associations Incumbent World Sailing President, Carlo Croce (ITA) has nominations from 45 Member National Associations [MNAs] for his re-election as the President of Sailing’s International Federation. Nominations for the position of President have been formally published by World Sailing and show widespread support for Croce.
Posted today at 10:35 am
Swiss stars Alinghi lose mast in collision in action-packed day
The Extreme Sailing Series™ lived up to its name on the penultimate day of Act 6 in Madeira The Extreme Sailing Series™ lived up to its name on the penultimate day of Act 6 in Madeira as a collision between rivals Alinghi and Red Bull Sailing Team resulted in the Swiss crew losing their mast.
Posted today at 3:23 am
Oman Air in peak form going into final day at Extreme Sailing Series
A fresher breeze on the third day gave the GC32 fleet a chance to give the spectators an invigorating show of action A fresher breeze on the third day gave the GC32 fleet a chance to give the spectators lining the shores on the south coast of the island an invigorating show of speed and action and it was Oman Air that led the way with seven podium places – including two outright wins – in seven races.
Posted on 24 Sep
Extreme Sailing Series – Red Bull Sailing Team collides with Alinghi
At 1515 BST today during race eight, Red Bull Sailing Team collided with Alinghi, resulting in Alinghi losing its mast. At 1515 BST today during race eight of the series in the Madeira Islands, Red Bull Sailing Team collided with Alinghi, resulting in Alinghi losing its mast.
Posted on 24 Sep
Sailing World Cup - Qingdao chances shorten as top tens confirmed
It was all about a place in the Medal Race on day four of the SWC Qingdao as top ten were confirmed in all seven fleets. It was all about a place in the Medal Race on day four of the Sailing World Cup Qingdao as the top ten were confirmed in all seven fleets.
Posted on 24 Sep