This is an interesting map that shows current Norfolk villages that produced salt in AD1086.
As you can see from the map most of villages that produced salt are inland, however to produce salt you need tidal sea water, which in turn
implies that the sea reached much further inland in AD1066
From our Sea Level rise page we estimate a sea level of about 4.7 metres higher than present in AD1086, the salt houses in Norfolk
fit this sea level height quite closely Please see the Scalgo derived Sea Levels at 4.7 metres.
Please Note - Our outlines of the coast and islands in Norfolk is nowhere as accurate as those from the Scalgo data.