(second attempt)
Yes John, it is indeed the old ship swallower. Cryptic clues would have been "Vespasian came here before he was emporer" (roman invasion of Britain) and "This man's son was a King and general" (King Harold Goodwinson). I'm including a larger and uncensored part of the chart. My initial submission was too big, I hope this one works.
If you look at Goodwin Knoll the drying height is 3.8m. With normal tides that means it stands about 2m above low water, but is hidden less than 2m below the water. It lurks there, just waiting to catch hold of your keel and add you to the Sands 2,000+ ships they've swallowed. Better keep a good fix!
Over to you.
