I took the Brightlingsea Duty Harbour Master's advice and contacted a couple of people on West Mersea about moorings and one said that he had a suitable mooring, so we made arrangements for me to visit.
It was a grey sort of day and I arrived just before low water. This is the view from the car park.
The public hard has two sets of posts that enable boats to moor between them and to prevent them from falling over when the tide goes out. The hull can then be worked on although there isn't much time before the tide comes back in again.
Another view of the hard.
The mooring in question is out there by the large motor boat. Not so easy to see in this photo so...
Here it is zoomed in. That vacant orange buoy is the mooring. Looks close to the motor boat but looks can be quite deceiving as it is some distance away.
A view down towards the open sea. As you can see it is fairly well protected.
This is the view in the other direction. I'm standing on a jetty sticking out in the river and there are two barges moored here that the fishermen use for storing their gear.
This is a bit further round looking back towards the public hard.
So, an available and suitable mooring and although not as cheap as the one I was going for in Brightlingsea, this one is accessible at all states of the tide which is very good news for me.