Tried for an adventurous shot today. Visited the local fish quay. Flew tello out over the side.
Almost immediately i got 'visual posituoning not available' and it started to drift back, away from me.
(Luckily it wasnt out into the river)
It probably depends on the visible field of view of the downwards camera. And as I remember the documentation states that bodies of water are not a great idea to fly over
Good thing nothing happend to your tello.
I also have flown the Tello over water! Once the drone lost positioning, drifted quickly down wind and ... out of range. When I reacquired the signal, I could not see the drone...so I increased altitude and looked around until I could tell with first person view how to return. It is easy to lose sight of the drone, especially when using a range extender.
The second time I flew over water, I was less than 20 feet and Tello went into auto land mode! The Tello got with in a couple of feet of landing on the water before I coached her back up into the air...i have video of that!
I will attest that flying over water is hazardous to the future of your tello. I still do it, but try to stay very close to an edge or other objects, (boats) in the water.
Nice and calm today so tried a second shot. Had a friend with me as a spotter to keep an eye on things, as it's easy to lose your bearings when watching the screen and the position of the drone.
Had a little backwards drift (with the direction of the wind) but vertical height was steady. Could have possibly gone further 'out' into the river but don't want to push my luck