GPS..........It really depends where you are using it......................
There are unsubstantiated claims that someone near the Gulf of Hormuz is broadcasting fake GPS.
Some ships in the area (you know...actually floating in the sea) have seen GPS locations reported as hundreds of miles inland!
Please tell me that sextants, sightings, compasses and paper maps are a thing of the past!!!!!!!
I suppose this sort of thing could happen anywhere......say in the English Channel.....