Country: UK
Address: FQFF+XM London, UK 
Swimming in the Thames is permitted, but only west of Putney Bridge (upriver of Putney Bridge through to Teddington). Anywhere else, it will probably get you arrested.
When swimming in this area it is important to note that vessels will be navigating, and it is vital for your safety to keep a good lookout and make yourself as visible as possible to other river users, for example by wearing a hi-vis / coloured swimming cap.
PS: Never swim across the river!
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