Sites with direct access to river for dinghy &

judder

Hi all - I have just bout a small inflatable dinghy with an electric outboard for use on inland waterways and potentially (calm) sea. I'm looking for a site (either club or otherwise) from where I can launch the boat a go off down an interesting little river
or lake etc.

Any ideas please - I live in South East England btw so round her best initially at least