I hope Jan might comment on these gulls - or anybody else of course.
The first two pics I took at Southwold boating lake last week. I reckon its a cachinnans, but have some worries about the bill length and shape, but in flight the underwing was white and the tail pattern spot on. Note: there has been some moult in the coverts and that these have now worn; there are some grey feathers coming in on the scaps, and that the pattern of the bleached and worn other scaps is quite variable. Long legs added to rangy quality of the gull.
The next two are of a 3rd cy white-winged at the harbour mouth, I saw with my dad. We wavered from Glaucous to Iceland, then back and forth. The size was that of a small Herring (though it looks bigger in photo it was not), surely an Iceland?? I seem to have lost all confidence at the mo....