I waited round at brightlingsea for an hour or more, after two bad experiences with motorists coming into town; it didn't take long. A couple of hours in Essex, and things get back to normal pretty quickly.
The wait was worth it though. I hadn't realised that I needed to make a phonecall before the ferry would turn up, but when I made the call it just rang. Then the ferry arrived. It already had customers. I asked about going to Mersea and was asked to wait. Then some people arrived to go to ------ which meant my trip was viable. The woman was nice, amiable, and we chatted. The ferry is new and subsidised; the price was lower than previous ferries, even though journey was longer, and view was better.
Some Mersea Island Links
Facebook: Mersea Island Notes
a walk around Mersea Island