One clarification, the full-scale version's max speed is ~75 mph, and typical cruise speeds will be 50-60 mph. The 35 mph number in the article is our subscale prototype. We loose range in a headwind, but on most days the aircraft has more than enough range to complete our target missions. And on the days the weather's too bad to fly, many other small aircraft are grounded too. - Joe from Buoyant