I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission not required.
Drive on past the train station at Leigh on Sea and just follow the road as far as it will take you. You'll eventually come to a small boat jetty with a quite large unmade car park on your right.
Further right through the car park is where the coastal walk starts. From here there are many open space from which to take off and land from.
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.