No interactions present.
The reason that I went for Shag is that one of the boks that I use for refernce [Collins Bird Guide 2nd edition - page 79] clearly shows the orange marking and a light grey lower bill and in flight it looked a bit slimmer than a cormorant.
Adult Shag does have a conspicuous yellow gape, but Cormorant has a yellow patch at the base of the bill just like this one. Shag also has a steeper forehead and more slender bill and neck than your bird. The green sheen would also have been evident if it was a Shag. Build can be deceptive in the field, but the heavy build in the picture is clearly that of P. carbo.
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
OK David and Syrphus and thanks, ID points taken and accepted.
Lat/Lng: 50.71481, -1.7453
OS grid ref: SZ180906