There are two large ships in that area at the moment both with huge upper superstructure the PRETTY LAMB a bulk carrier, and the SEREN a general cargo vessel
I think it might have been this https://www.devonlive.com/news/devon-news/what-massive-strange-looking-ship-3529838
According to the article it is on its way back to Denmark from having been doing work in the Irish Sea and then Swansea in s. Wales.
Next weeks headlines in the Dawlish Gutzache.
"Ship seen off Dawlish. Mass panic and rumors spread throughout the area".
Sorry to disappoint you Lynne but the position of the MPI ENTERPRISE as i type is latitude 51.69655 longitude -4.948534 and that is Pembroke Dock.
There is a structure out at sea that is only visible in certain conditions, I can't remember what it is but it has been there for years! Perhaps that is what Lynne has seen. It is weird that it is only visible in certain weather conditions, I have observed it one day from DW and the next day cannot see it at all.