This one is an art installation by Tees Valley Arts
Its pretty hard to get near, that photo is on 12x zoom but the local wildlife seems to like it.
Update : The work is called work “Mirage†and made by Tony Charles
Mirage Mirror Boat – Coatham Marsh
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Looks to be popular with the Shelducks.
Went today 22/06/18 and looks as it’s been moved as chatted with a few local people who didn’t know off it’s existence and the water level has lowered