Gull numbers seem to have dropped in the area. No white wingers today . 4 adult and and 2 1stw yellow legged gulls also.
Edit: If this caspian like gull is a 2nd winter gull then it may well be a caspian gull but if it is a 3rd winter then it probably is not. The small white spot on the primaries may suggest this bird is a 3rd winter bird. It would have been nice to have managed better images and views of this interesting bird.