Great Black-backed Gull?
juv Iceland Gull
I tried hard to relocate it but it seemed the bird had moved on. As a final resort, I headed for the docks to see if it had roosted there, on the way connecting with the usual Slavonian Grebe and my first Wheatear of the year! When I finally arrived at the docks, it was clear the swell out to sea was putting the gulls off from roosting offshore which gave me a good opportunity for an unsuccessful check of them before darkness and rain started falling fast.