Naval base to wear cost, stripping second ships (5)
I believe the answer is:
fleet
'ships' is the definition.
(eg a naval fleet)
'naval base to wear cost stripping second' is the wordplay.
'base' says to take the final letters (the base of the word).
'to wear' indicates putting letters inside (to wear something is to be covered up by it).
'cost' becomes 'fee' (fee is a kind of cost).
'stripping second' becomes 't' (2nd letter of 'stripping').
The last letter of 'naval' is 'l'.
'l' put inside 'fee' is 'flee'.
'flee'+'t'='FLEET'
(Other definitions for fleet that I've seen before include "Fast - naval ships" , "Navy - quick" , "Quick of foot" , "group of taxis, for example" , "Collection of company cars" .)