This is a route that was used in a Southend Bikeathon. I think it was 2010. The route takes in part of the Southend seafront cycle lane before heading off towards Barling and then looping back to Shoebury going through Great Wakering. There is a very busy roundabout 4 miles into the course. If you do the course the other way round, this is easier to navigate.
Southend Bikeathon 2010 Route