At Spithead, they're properly sunk! (5)
I believe the answer is:
wells
I'm afraid I can't explain this answer.
Can you help me to learn more?
(Other definitions for wells that I've seen before include "Cathedral city; sci-fi writer" , "Author" , "What a boring person might produce" , "H. G. . . . . ., science-fiction writer" , "Springs" .)