Extraordinary boats The kite-powered Armorkite 650
FRANÇOIS TREGOUET ON THE ARMORKITE 650
The Armorkite 650 is a Mini Transat-style yacht sailed under power kite, with no conventional mast or sails
It’s a grey and wet February day on the pontoons at Port la Forêt, the Mecca of French single-handed ocean racing. Olivier de Kersauson, a man never stuck for finding the right words, once renamed the place ‘La vallée des fous’ (the valley of madmen). Michel Desjoyeaux, Armel le Cleac’h or Jean Le Cam, all prominent locals, take this as a compliment. But standing in front of this boat (I’m not sure we can even call it a sailing boat?), without a mast, boom, stanchions or any apparent sailhandling gear, I’m beginning to wonder if that local madness isn’t contagious.
At first glance, the Armorkite 650 is as intriguing as its deck is empty. To sail it, we’ll clearly have to forget everything we’ve learned to take for granted. What’s more, even though it’s not apparent at first glance, there’s no keel, or even ballast. Stability comes from the hull form, thanks to a 2.2m (7ft 3in) beam, and a design reminiscent of the Mini Transat 650 class. So it comes as no surprise that the Armorkite’s architect, Etienne Bertrand, not only took part in the legendary transatlantic race back in 2011, but has designed some 15 of the development boats.
Armorkite’s Maxime and Marc Denoix gave me a quick briefing before we headed out – and it was brief. The Armorkite has only two lines for trimming, and a tiller; the boat can be sailed double-handed easily. Pushing off from the pontoon by hand and getting out of the harbour powered by the small outboard is particularly easy with a hull weighing only 273kg (602lb). With no ballast or rig and therefore very little structure, weight is kept to a minimum.
Once out into the bay though, our sail radically differs from a traditional outing. First, a drogue is deployed astern, to limit drift while we prepare and ‘hoist’ the kite. Even more unusually, we contact the Coastguard by VHF to warn them
about our forthcoming test sail: twice well-meaning sailors have triggered the rescue services after seeing a boat without a mast, apparently dismasted and trying to set up a jury rig while deploying the kite!
The wind is light, around 7 knots, the theoretical minimum required to get the kite off the water. So we take out the biggest sail, at 25m² (270ft2). There are five size options, at 8, 13, 21, 23 and 25m² (89, 140, 226, 248 and 270ft2) for all types of wind from 7 to 35 knots. The kite is placed on the coachroof, well-flaked in its sailbag, and the five lines connected (two forward lines, two aft lines and a fifth line) to the boat via an athwartships Harken track. The kite flies free and to leeward as we go upwind, thus limiting any heeling, even though the design allows the Armorkite to heel up to 15°.
Once connected to the boat, the kite can be unfolded and the leading edge inflated using the on-board electric pump. Having inflated the kite, all five lines are unwound simultaneously using the electric winch. With Armorkite’s board sports specialist Thibaud Grasset at the controls and Maxime Denoix at the helm, they launch the kite in perfect rhythm – but they do have more than 50 outings under their belts. This is useful because in this low wind range the kite tends to stick to the water, and take off can be tricky.
Eventually the wind picks up to 9 knots, the kite launches, the drogue is brought back aboard and the boat takes off! The speed is immediately exhilarating. We make a few tacks, sailing with the wind on the beam, going at almost the windspeed.
The Armorkite is extremely sensitive on the tiller, and also sensitive to the positioning of the crew, whose total weight can easily equal that of the boat itself. It’s important to keep a close eye on both longitudinal and lateral trim. A central footrest would help you keep balanced at the helm, but the sensation of gliding across the water is delicious. We don’t get close to beating the record of 19 knots the team has
already achieved, but sailing at 10-12 knots when the true wind is barely 15 knots is more than enough to put a big smile on your face.
When it comes to turning up to close-hauled, sceptics will say that a kite can’t go upwind. But the Armorkite holds a windward course that is comparable to a keelboat, sailing at 30° either side of true wind, at speeds very similar to a
Mini 650 of 6-7 knots in 10-12 knots of wind. But where the boat becomes even more impressive is downwind. We had 9 knots showing on the
GPS with 11 knots of wind dead astern. What conventional boat could offer that?
The power developed by the kite is impressive, and at times surprising; you have to hang on for the gybes, for example. More importantly, if there is an error in the angle of the rudder or the kite, or a lack of synchronisation between the helmsman and the trimmer, instead of the pulling power being transformed into speed, it tips the boat on its edge.
We experienced this during a wild ‘downloop’; Denoix had his hand on the automatic release of the fifth line, and the boat came back down the right way up – unlike the two capsizes they’ve already experienced during test sails, when they had to right the boat like a dinghy.
So, if there’s a foiling revolution underway, will the next be a kite revolution? There’s quite a way to go before this solution could be universally adopted. Even if learning to handle the kite takes just a couple of weeks, according to its inventors, the constant attention and adjustments required to the kite during sailing put a real brake on its usage outside of competition.
Although they are tempted to test their radical design’s performance in an event like the Bol d’or, or even the Mini Transat, the designers admit that they don’t yet know how to manage the necessary sleep times over such a long period.
There are so-called self-stable kites, but they are no match in terms of performance, with speeds reduced by 50-60%. At present the choice is between performance and peace of mind. The challenge is to reconcile the two, possibly through the development of a kite autopilot, or by adopting a faster furling winch to bring the kite back on board quickly.
In the meantime, a second boat is trialling some design modifications, including a single pivoting centreboard. This saves one manoeuvre, as the asymmetric daggerboards require moving each time you tack or gybe. With an autopilot at the helm, the whole thing starts to look like a very enjoyable dayboat: simple, efficient, fun and easily transportable.