a comment on one of the posts about whether they have any navaids so they can be identified to shipping.
The answer is no, which could partly be related to how they are historic objects and partly to the fact that they are typically close to shore in drying parts of the Thames estuary, well away from the shipping channels.
However they are marked on charts, which you can see for yourself above (the one off Chalkwell / Leigh / Southend-on-sea) and below (Yantlet Creek), in both cases taken from the Navionics Webapp.
There was no sign of the lost Yantlet or Lobster Island, washed away over the centuries, though I did notice an anchorage at the inlet to Yantlet Creek.
This remote location had no yachts bobbing at anchor the day I visited, though some yougsters did zoom up and down the creek in a jetski: