I spent a couple of hours this morning searching for the reported Thayer's gull and met up with a German birder called Sebastian Siebold. If he's not in your group I should track him down through ebird. He's meticulous, experienced and now resident. He'd be an asset to the group.
That aside we found at least 7 probably more Iceland/Kumlein gulls a beautiful 2nd year Glaucous gull and Sebastian found the Thayer's looking exactly like it's pictures on ebird.
Add to that a fly over adult bald eagle and 14 duck species including one each of white winged scoter. American wigeon and pintail and it was a very successful morning.
Regards Graham Langley UK birder and regular visitor here