I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission not required.
Access easy to the river bed at low tide via various paths. Allowing take off and avoiding the coastal path to the south which is on National Trust land.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 27/02/2021. It remains the responsibility of any pilot to check for any changes before flying at the same location.