ajohn

The larger 3 birds look like Dunlin - common in Deep Bay in winter. Curlew Sandpiper should look slightly slimmer and longer billed. Also, the rump is white (although this is not visible on the photo). Two birds seem to have a hint of the dark belly mark of breeding plumage.

The two smaller birds (one at top centre, the other hiding behind a dunlin) appear to be Red-necked Stints.