I am guessing since the sightings don’t occur over land that might be because no one is looking for them there. The Navy is very keen on sensor technologies, an

I am guessing since the sightings don’t occur over land that might be because no one is looking for them there. The Navy is very keen on sensor technologies, and trying out new, more powerful ones. These are always tested offshore. Any rival power that wanted to keep tabs on them would be in the vicinity of the sensors being tested.