Handy Andy, I had a brief stint (18 months) living in and around Sounthend a few years back, try asking in the fishing tackle shops on the front (Jetty Anglers in Thorpe Bay was where I used to shop, if memory serves).
They should have all the intel you need regarding what's good and where
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
just remember to purchase a few little bits at the same time, it always helps to loosen the shop-keeps tongue!