Apparently, they’re not just for kite surfers anymore. For the 2003 Americas Cup BMW campaign, KiteShip developed a real innovation in spinnaker design: on that really flies. The team didn’t feel they had enough time to master the new sail in preparation for the Cup, but the concept seems to work, and their are many advantages: namely a downwind sail that won’t stress the mast or cause the boat to lose control. The kite provides lift as well as driving force, which keeps the bow up, which is an added safety margin for multihulls. The main disadvantage I can see is that it needs a full crew and three winches to fly and trim, so that rules out short-handed and cruising use, at least at the current stage of development.