Ships - they protect against surface damage (8)
I believe the answer is:
coasters
'ships' is the definition.
The definition and answer can be both man-made objects as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for coasters that I've seen before include "Small table-mats" , "Merchant ships with a limited range of operation" , "Small mats for Socrates" .)