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The 2008 European Championship, displaying some spectacular sailing and speed of Bob Baier on his Nikita equipped with curved centreboards, seems a long time ago. Since then the global A-class community has witnessed a debate within its ranks on the topic of allowance and if so, to which conditions, of the use of curved centreboards. A wise decision by the A-class has emerged, at least the real foiling is discarded, or so it seems to have been the intention... read on  . In 2010 we have seen about any available brand (even the conservative Marström) introducing curved boards so probably by 2011 virtually no new boats with straight boards will be leaving any production hall! Today, the end of the European 2010 sailing season is luring. The national and World championships have been sailed, new models have made their introduction in the class, new developments are promised, new players are emerging and the odd surprises (Jack Benson's third place in the WC on a good old Flyer 1!!) fuel again new debates. In fine, the pressure can take its time again to build up for next season (at least at this side of our planet!). It has been said so often that the A-class catamaran is the formula 1 of the one-up sports catamaran. I couldn't agree more! I even recently had a top Formula 18 sailor telling me that he'd rather not try my boat because he is afraid he would like it too much and he's basically happy with his F18  What more compliment do we need ? But is there a danger that the power of attraction may be reduced? Sure, due to its low weight, relatively narrow beam and high rig the A-class is no boat for beginners but a couple of years of experience largely suffice to get access to this class and taste the boat's speed potential. Now, to get the last percentages of speed, it does take a while to understand all the dynamics and practice to convert them at all times into those extra tenths of a knot. But it would be fair to say that this is applicable to all sailing and to all sports by extension. What can we expect in near-future developments within the A-class? Well, I am not a builder of any kind (I only seem to be able to destroy boats or masts  ) but some reading and talk left and right give an idea of at least two different directions; 1. as you can read in another article on our website, the pairing of a sail and the mast is re-looked at. In my English (I am Dutch speaking mind you  ) this means as much as; the masts of today may find themselves to be obsolete in a not so distant future and so will the sails as the first may either change shape (in the top third only?) or its bending characteristics and this automatically affects the sail... In all fairness, this point is something that is on-going for decades now so hardly anything new there (though very important).
2. with the acquired knowledge about how curved centred boards (should) work, we will now start to see extra refinements and this may radically change the (joy of) sailing A-class catamaran.
OK, what do I mean with the latter statement? Well, centreboards have changed in length and width just like the position of their casing since the class exists (or so I assume) and their use is pretty standard as well, even across catamarans and dinghies. Downwind, boards up, upwind, boards down. Simple and applied by both the Ashby's of this world as by the 8- year old sailor on his Optimist! What we witness now, with the curved centreboards, is that there are a few parameters extra coming into play. In the early days of those centreboards it was claimed “it will be even easier with curved centreboards as they stay down all the time, no need to touch them under any angle”. Nowadays, it says “yes, but not when there's a (very) light breeze”. I can live with such exception, as it comes back to the old rule on centreboard usage. But , now it turns out that the following things play a role as well, and they depend on the wind, the amount of swell, the angle sailed and the weight distribution on board mind you  ; 1. the shape/curve of the centreboard as a whole (including the way the edges are (not) rounded) 2. the vertical rake of the board 3. the horizontal rake of the board (i.e. adjusting the angle of attack of the board in the longitudinal way) 4. board depth (as mentioned above)
So, instead of having one parameter less to take care of, we find ourselves with 3 extra parameters! 1. Is it unthinkable that according to wind conditions a board with curvature b is put on the boat instead of the one with curvature a? The way the leading edges of the centreboards are finished also play a role, they may be neutral or finished in such way they give at all times a slight upward momentum (see point 3 below) or is this done on the trailing edges... 2. At least one boat already offers the possibility to adjust the vertical rake of the boards while on the water so number two is there already! 3. To my knowledge no boats with a horizontal rake adjustment is on the market but that may only be a matter of time. To explain this parameter simply; if you have the curved board to point upwards in the horizontal plane, then it will exercise an upward (lifting) force on the board and hence the hull. This is true if the boat has serious speed and the angle is not adding more drag than upward momentum.  In a reverse way, the hull is 'sucked' into the water. Will such adjustment feature find a way to a boat?
As you can see, these parameters are not there to make our lives easier. In fact, in my modest opinion it will further increase the knowledge (and hence training time!) of the boat dynamics and the question is how many of us have this extra time, patience and money because no way such new systems will come at the price of a straight board!! These systems will need to be adjustable on the water depending on the wind, the type of waves and the seating/trapezing position (hope I haven't forgotten any). Or will they not? Will they be a bliss or a curse? Finally, just to get us all going I would like to refer to an interesting interview of Martin Fisher which may seem all of the above very modest developments … http://catsailingnews.blogspot.com/2010/05/cs-interview-martin-fischer.html good reading and till next season? Regards, Michel |
