Left: the story is just getting started as designer-builder David Raison (helming) takes the original Magnum for an early sail in the summer of 2010. After 12 months’ development the same boat – the first modern scow in the Mini Class – would wipe the floor with the 2011 Mini Transat fleet. It’s taken over six years but 2018 will finally see the launch of Raison’s first Series Division scow (above), a little bit heavier, a little less sophisticated and less powerful but remarkably similar in overall design to that first prototype, opposite
enormous. Offwind during his first Mini Transat victory six years ago Raison was reg- ularly sailing 2-3kt faster than all his rivals. Today there are still only a handful of
scows in the Mini fleet but the numbers are growing (scows filled the Transat podium). Raison’s ideas are gaining wider traction and many new ‘conventional’ designs lining up for the big event of 2017 showed much fuller bows and flatter forward sections than would previously have been the norm. New scows from Etienne Bertrand, Mer Agitée and Romaric Neyhousser all showed consid- erable ‘bow inflation’! But Raison is still ahead as race-winner Ian Lipinski nicely demonstrated with the 2014 design Griffon. When you sit down with him you quickly
realise that David Raison is not a ‘regular’ yacht designer nor a typical Transat-win- ning skipper; if he was originally convinced that lightness was inseparable from the scow concept he had the opportunity to review his stance with the design of the Revolution 22 and Revolution 29… not Mini protos, but a pair of scow-shaped cruising yachts that he designed for AFEP Marine. ‘I was a little reluctant at the beginning of this adventure to try the concept in this way,’ he says. ‘But ultimately these ships have behaved
more than honourably for their respective purpose. Heavy scow shapes built in alu- minium with plentiful onboard comforts and equipped with a lifting keel! ‘But it works! Amazing, no? Light is
beautiful but not mandatory. It’s about the package. And a nice bonus is that as these boats get larger so the aesthetics become less strange as the relative freeboard decreases.’
A REMARKABLE FEW YEARS Seahorse: Firstly congratulations on another Mini Transat victory for your designs. Tell us how the design changed from your 2011 Mini to the boat that won in 2017?
David Raison:My first experience of sailing scows was the Melges A and C scows which race on the US lakes. They are magnificent boats and they inspired me to design a ‘similar’ boat for the Mini, but of course within class rules and with enough free- board to be raced across the Atlantic! In anything other than a short sharp chop or extremely light winds 747 is the fastest Mini when sailing upwind. Ironically its only real fault was that it tended to bury the bow and slam a little when reaching fast or sailing downwind in large waves. With 865 the design was further adapted
towards oceanic sailing – the boat is slightly slower than 747 upwind, but slaps into waves less with the spinnaker up and aver- ages higher speeds over a typical offshore course. There has been an enormous amount of CFD work behind this develop- ment – much more than would be the case even on many Imoca programmes. SH:And will we see a new Raison Mini winning the 2019 edition? DR: I hope so! So far my designs have competed in the Prototype Division but as you know I have just finalised a Series Division scow. IDB Marine will launch the first boat in May. The boat is fundamentally a similar design to 865 but modified to meet Series Division rules (GRP construction, aluminium mast, no canting keel, no water ballast) and with a little extra rocker to compensate for the extra weight that comes as a result of it being a series boat. With the extra shell and deck area the series scow will be 25-50kg heavier than other popular series designs but around 250kg heavier than the Proto (dry ship). Actually IDB had never created a proper
racing yacht before but Denis [Bourbigot, IDB owner] is an experienced Mini racer who built his first Proto in the 1980s (more recently he has also been experimenting with
eco-materials and built a Julien Marin Mini with flax fibre in place of carbon/glass). The IDB Mini has a resin-infused monolithic glass/polyester hull shell (monolithic con- struction is mandatory in a Series Mini) with a PVC foam/polyester cored deck. However, the hull shape will be essen-
tially identical to Lipinski’s Griffon. The keel will have an elliptical trailing edge, giving the right balance of sideforce and low drag as well as allowing a short chord in the draggy area where the fin meets the hull. The L-shaped keel/bulb allows us to
move the mass aft without shifting the centre of lift aft as well. I prefer the centre of lift to be a little forward to load up the rudders, meaning they deliver lift efficiently and give a better feel for the helmsman. There is a ‘slot’ shroud arrangement (with
the D1 tucked inside) with boomerang first spreaders to maximise headsail size – which is important on these boats since the main boom and sprit must be shorter in the Series class than on a Proto. We just try to squeeze as much canvas as possible into the space we are allowed. SH:And your foiling Mini… DR: My current employers [SEAir] have modified my original 747 design to become fully foiling, using a similar system to the one we use on the foiling RIBs we are now developing. Currently the boat does not meet the Mini class stability requirements so we will either have to add some ballast or reduce rig size slightly to get within class rules. It is not confirmed yet but I hope that Bertrand Castelnerac [an accomplished pro- fessional sailor and SEAir co-founder] will race the foiling 747 in 2019. We have been testing the boat for some time and it is around 30 per cent faster than 865 over a typical Mini Transat course! So if all goes to plan my boats could win the Proto and Series divisions next time! w
SEAHORSE 37
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