David lowered his drone closer and closer to the roaring mouth of the hole. Then, suddenly, his drone started to wobble and shake, dragged off course. Fortunately, then, he is an experienced pilot and knew exactly what he was doing.
“When I lowered the drone into the ‘Glory Hole,’ it became unstable and almost crashed into the side,” he explained. He therefore quickly guessed that the rush of draining water was creating a vacuum. This was making the drone unstable as he flew closer to it, though – so he struggled with the controls to correct the drone’s flight path. Finally, he was able to pull his drone up and out of a potentially disastrous collision course.
If he had failed, David would have found what remained of his drone some 2,000 feet away in Putah Creek. Lake Berryessa isn’t, it’s worth noting, a natural lake at all. It’s the seventh largest man-made lake in California, having been filled in the 1950s following the completion of the Monticello Dam.