High-performance hobbyist drones are approaching UFO levels of performance.[1] Top speed of that one is well over 400MPH. One of those will cost you maybe US$8000. The triangular craft seen buzzing US Navy ships off the coast of California look a lot like those.
There's a huge range of remote controlled aerial vehicles you can buy now.
Speed is extremely easy to mistake if you have in your head that you're expecting objects of the size piloted by humans. Further if you're not triangulating the distance, any claims of speed are just pure nonsense.
There's a huge range of remote controlled aerial vehicles you can buy now.
[1] https://www.youtube.com/watch?v=DPGDAZyQ44k