Been fairly murky all day here, with mist coming up the valley this evening too. A late afternoon visit to Black Hole Marsh did not give the hoped-for close views of the Semipalmated Sandpiper - though it was visible at some range across the river from the Tower Hide, with about 20 Dunlin and 3 Ringed Plovers. Then a helicopter flew low down the river and flushed everything.
Apart from the Yank peep, best bird was an adult female Marsh Harrier which loitered in the area until I left, drifting up and down, mostly quite high. Here are some amazingly poor photos, in which you can just about see what it is...