Ha! you beat me to it amymay this is what they say for Essex:
Southend Beach - the dog friendly bits 1) Thorpe Bay Yacht Club west to point where loading jetty used to be - near Sealife Centre. Jetty now gone, but the concrete platform remains at the top - at the sea it looks a bit 'scruffy' with bits of wood sticking up from the sand. 2) West of Three Shells Beach to Crowstone Avenue in Chalkwell. 3) Chalkwell Station west to Old Leigh Beach 4) Whole of small beach at Old Leigh which is technically a slipway. I got this from one of the people in the foreshore office so I know it is ok for dogs to walk on these areas all year round (June 2008) - they prefer them to be on lead near kiddies, but it's not compulsory. DFB site user suggestion.
I was planning on making this post in the near future...
Bob and i are planning to move to Chelmsford area after Christmas so will be making a few seaside trips!