You may have seen some photos or have heard about the 'Balanced Sailing Team' A+ Cat project.  Whilst not an 'A' Class, it's basically, an 'A' Class on steroids with a wing.  Oscar Lindley-Smith reports on his experiences of sailing this boat at the recent Foiling Week event at Garda.

What is the future of high performance small boat sailing?  It’s a question which is continually being asked by designers throughout the sailing industry.  Will the Moth concept continue to reign as the fastest boat around a course or will the current frenetic development of the A class allow it to catch up and also achieve the illusive 100% foiling around the course? The part the A+ plays in this game is asking the question: does a wing sail on an 18 foot beach cat actually increase its VMG and produce a boat which is faster around a course?

Weighing in at 107kg she is about 30kg heavier than a standard A class. This is partly down to adding an extra 2 feet to of beam to increase the righting moment and thereby reduce the risk of capsize meaning she is now 10 feet wide (3m).  But the hulls themselves are otherwise identical to a standard A class and most of the extra weight comes from the wing itself compared with a soft rig.  Something I hadn’t fully appreciated, having only previously sailed a wing rigged boat for 30 minutes before taking the helm on the A+, is how differently the boat handles: the increased weight and higher centre of mass results in it pitching forward faster on bear aways and once heeled past a certain point you could feel it pulling you over.   The other challenge the wing posed was in manoeuvring where I had to go around the trailing edge and this coupled with the weight and rake of the rig meant the transoms would dig deeply into the water killing my speed.  To overcome this I adopted the ETNZ technique where I would throw the boat around the tack as fast as possible then run to the other side.  This actually worked very well as with the C boards currently fitted it would result in something close to a roll-tack as the rapid unloading of the leeward board through the tack would raise the hull out of the water helping me tack faster. More work is definitely needed to refine this technique however!

The one-off bespoke wing on the A+ is a major feat of design and construction that has taken hundreds of hours of work from Sito at Balance .  I was very aware that any capsize would likely to result in extensive damage.  For obvious reasons during these early sails we were careful about the wind conditions in which we sailed the boat. 

The most obvious challenge posed by the wing however was its sheer size.  It had to be transported and stored in a 40ft container throughout the event and the rigging takes at least 3 people.  With all these problems surrounding the wing there clearly has to be a major speed advantage to justify them if a wing is going to find its way onto more mainstream boats:  But boy was this there!  First sail out I matched up with Paul Larsen on his Exploder AD3 and as expected in the light wind (7-8knots) and flat water the A+ blew him away upwind on my first sail helming a wing rig.  The performance on that first sail was breathtaking, yes I was expecting a lot but I hadn't imagined such a huge leap in performance.  Sailing that much faster than the fastest sailor on the planet would put a smile on any competitive helms face!  The A+ simply sailed higher and faster than the standard Exploder AD3.  Now this was in the absolutely perfect wind range for me of 7-8 knots where thanks to the 18.5m^2 of wing area I had heaps of power on tap.  I was fully powered up whereas the A class couldn’t foil upwind. The situation was reversed on a reach however when the A could ride its foils and pulled away from me, as did the Moth I matched up with the next day.  But how often do you sail a beam reach on a course? Downwind was more challenging with Paul foiling away from me to begin with while I was trying to find the groove for the A+.  It took a while and will still require a lot of work but I managed to close the VMG gap towards the end.  After less than 6 hours of sailing it’s still early days and there is without doubt a whole new world of performance to tap into on this boat.

One of the main objectives behind developing the boat was to demonstrate that it can effectively be done on such a small scale and that it then results in a fast boat. To create a quick boat, especially a single hander, requires simplicity and elegance in your control systems and this was an area where a lot of time was spent.  With only 3 control lines for the wing, plus the mainsheet, this is no more than for a soft sail.  Whilst the boat is not yet fully foiling, she has C boards which according to the CFD models show they will lift the boat at 20 knots, however, my experience on the boat showed that with some larger rudders she will be taking off much sooner than that. The reason not to attempt to foil straight “out of the box” was something we debated for a while and in the end was decided against due to safety in the learning process.  We felt that there would be enough going on at already high speeds without the added challenge of fully foiling from the first sail.  We also feel that the optimal foiling solution for a single handed multi hull is is still very much under development:  The non class-legal L/V boards we trialled on our A Class required you to grow another pair of hands to be able to sail it effectively in a race setting.  Clearly this is not the answer.  But the option of copying the current A class solution is not ideal as it reduces the righting moment. Why go to the effort of increasing the beam to then reduce it again?

After this first week of sailing there are a few small issues that need to be addressed but overall the boat performed to expectation and we are looking forwarded to getting her back on the water to continue the development and to hopefully show enough potential to pose the question: is this the future and can it with some development be used by all high performance beach cats?