The folks over at Freefly Systems have invented a new sport called Dronesurfing. This isn’t an autonomous or robotic surfboard that can be remotely controlled. Dronesurfing uses a flying drone pulling a towrope that a surfer can grab and get pulled around the water on some sort of thin surfboard that looks like a wakeboard.
The result is very impressive, to see a drone with enough thrust and power to pull a man on a board through the water. The drone used is a Freefly ALTA 8 that packs in eight different rotors and is quite large. The unfolded diameter of the drone without the props is 1325mm. It has eight direct drive 3-phase PMAC out runner motors dubbed Freefly F45.
Each motor has 350W continuous power output and 950W maximum peak power output. Maximum RPM of each motor is 6300 RPM. The propellers are made from carbon fiber over a balsa core. Power for the drone is from batteries with a pair of packs in parallel. The maximum takeoff gross weight is 40 pounds with a maximum useful load of 26.4 pounds. Maximum payload is 20 pounds. Towing a human on a surfboard seems to be much more than these maximums.
There is no indication that the drone was modified to pull the person. Freefly Systems did note in the comments for the video that it was doing 3-4 pulls per battery set with each pull lasting about 30 seconds. There is no indication of how much the surfer or his kit weighed. The fact that the drone can pull him and stay aloft is impressive, check out the video for yourself.