KITESAILING: THEORY AND HOW TO Getting skilful at buggying is of great assistance for kitesailing but kitesailing poses a whole new set of problems. On the plus side under water foils can withstand huge sideways forces, even at quite low speeds. In fact there seems to be no practicable limit on resistance to side pull - the limit is capsizing or leaving the water. This is not as bad as it seems. It's when you come down that the big problems occur! My 1992 model kitesailers are quite versatile - under 20kgms packs to 2.15m x 0.6m x .2m. 3.3m x 1.75m x .6m assembled, capable of sailing upwind in the wind range 5 km/hr to 100 km/hr winds (in the extreme limits). I tried many different layouts but against theory, the one hull in front, two at the back seems to work best. Two hull layouts don't turn fast enough. Two front, one back is too complicated (steering) has a wave drag problem (bum clearance) is heavier and seems to tip easier. Mono hull layouts are just not satisfactory at this time. Kite pull varies so much they behave like Pooh Bear's honeypot, being much more interested in floating with them on top and you underneath than in the conventional air breathing relationship. Nothing is settled yet though. A practicable zero heel system for attaching the kite to the boat structure would re- open the layout options. One thing I think I know for sure is that for kitesailers the rudder must be at the front. Having the rudder at the front effectively eliminates the otherwise frequent occurrence of "getting caught aback" - the "nose into the wind kite pulling over the stern" scenario which generally precedes the "big turnover"! I believe that planing hulls are a must for high speed but we are not yet attaining speeds with the kitesailers that can be easily maintained using kite powered water skis. Also I am awed that a Flexifoil stack powered "Tornado" catamaran (displacement hulls) has averaged 25kn for 500 metres. I can't get anywhere near this average yet, couldn't even do this speed momentarily and certainly regard the 38kn for 500m reportedly attained by the Durand kitesailing team in France as being from an alien universe! Of course, I have been aiming at developing an easy to use, safe, inexpensive, all normal sailing courses, broad wind range kitesailing boat to be widely available and I have not yet had the privilege of sailing along the especially constructed, flat water, high wind, downwind course, "French Trench" speed sailing course! But, kitesailing is now practicable and accessible. The big problems, interelated, are: absence of an usable on the water kite relaunch system (I'm trying!) and apparent wind luffing kite collapses which are a much more serious and intractable problem for kite boats than for buggies. The theory for kitesailing is very much as for buggying particularly with respect to kite requirements and flying techniques. Because, as yet, relative kitesailing speeds do not approach the 3x and more multiplication of true wind speeds available to buggiers low kite M.M.R. is a greater requirement. Paradoxically kitesailers manage higher relative speeds in light (less than 10 km/hr) winds than buggies do. Boat drag rises from zero at zero speed, buggy drag starts at about 5kgms but doesn't rise much with increasing speed. Because boats also have to contend with waves and a higher drag penalty for available leeway resistance, their upwind performance is not as good as for buggies.