There are extensive areas of seaweed-covered chalk around the Thanet coast (similar to those seen at low tide off Kingsdown). These rocks attract waders and gulls who roost and feed on them - when the tide comes in, of course, the rocks shrink and then are submerged, and this period a couple of hours before full tide becomes quite interesting.
These pictures show Turnstones, Knot and Purple Sandpipers watching their chosen rocks slowly sink beneath the waves.
Meanwhile, some Ringed Plovers are standing on a nearby 'island':
The Knot's latin name is Calidris Canutus - very appropriate in these photos. One of my first 'wow' moments in birding was seeing photos of waders on a rising tide at Hibre Island; one of my most recent such moments was watching (on TV) swirling clouds of knot at Snettisham.