Wing of the dragon

That's Phefo's test sail on solid ground. We broke the experimental mast four times. Always at the same spot (2 battens up). No standing rigging. No winches. Drop all 4 sails in 10 seconds. 4 sails? Yes. 4 masts. Although it looks just like a junk sail, it is actually a high technology, cutting edge performance propulsion unit.