I've just watched Estuary, a short film about the Thames estuary by Southend Festival director Rachel Lichtenstein together with film-maker James Price. As the blurb puts, it "with the grey water lapping at the prow, they sail from Queenborough on the Isle of Sheppey across the shipping channels to Southend pier."
All very arty stuff - you can watch it here.
Rather topical, given there is currently an unexploded WWII mine floating around in those waters. Apparently it was dredged up and then escaped before it could be safely detonated.
A case of one our mines is missing.
Updated: now exploded, see video clip here.