Finally we bumped into Richard 'the Hat', who told us where the Scoter had been seen and also that the Egret was out of sight. Accordingly we trudged across the beach (following a receding tide) to the water's edge. Quite quickly we picked up a group of perhaps six or eight Scoter, one of which seemed to have a pale region on its neck. (I have enhanced the first photo by increasing the contrast and reducing the gamma.) Typically, when three flew towards us, the putative SS stayed put! (I hesitate to say this, but there was at least one Red-necked Grebe out in the bay too.)
After half an hour or so, we walked back to the pines, where a small group pointed out the GWE right across near a herd of cattle by the road at Burnham Overy. Since our parking ticket was due to expire, we walked back to Lady Anne's Drive, where a small crowd was clustered around Martin's car. Not a parking fine, I'm pleased to report, but a somewhat distant small Canada Goose.
We drove round to Burnham Overy, only to find that the GWE had moved back to the pool by the pines. We had been standing right by the fence at the base of the dunes!
To Cley for coffee and then home!