Lots of interesting and unusual species seen from a day at Spurn Head and surrounds:
469) Eurasian Hobby
470) Common Crossbill
471) Manx Shearwater
472) Sandwich Tern
473) Roseate Tern
474) Purple Sandpiper
475) Common Eider
476) Common Scoter
477) Grey Plover
478) Brent Goose
53) Common Seal
Other interesting things included a variety of waders that were my first European sightings for the year but I had seen earlier in the year in Thailand such as a really close view of a Curlew Sandpiper and also huge numbers of many waders. Although I did miss a few unusual species that had been seen in the area over the last few days (such as White-rumped Sandpiper and American Golden Plover), I'm really pleased with what I've seen today and having a scope with me proved invaluable despite being a right pain to carry around.
That should be everything that I can identified, though I may be able to ID a few more things from pictures if I have another look later.
When I get around to it, I'll check what my Europe-only (Poland + UK) year list is, I'm sure it must be my highest ever.