So, how did the gull get the whelk out?
I didn't see the whole process but it started by pushing the shell into the shingle on the beach, held it in place with its feet and appeared to use its beak to extract the contents.
Thanks for that; does it suggest a learned process? Did you observe if the gull got the whelk by diving for it? I think these big specimens are usually sub-littoral, but maybe it was washed up on the beach. Perhaps it was already dead as it has not retreated and closed its operculum in defence. There is always something new to learn on the beach. I love it.
New photo added which might help. The gull was on the water when it acquired the Whelk.
Lat/Lng: 57.5, -4.1
OS grid ref: NH7555