Escape, needing time away from Navy (4)
I believe the answer is:
flee
'escape' is the definition.
(I know that escape is a more specific form of the action flee)
'time away from navy' is the wordplay.
'time' becomes 't' (abbreviation).
'away from' is a deletion indicator.
'navy' becomes 'fleet' (I've seen this before).
'fleet' with 't' removed is 'FLEE'.
'needing' acts as a link.
(Other definitions for flee that I've seen before include "retreat" , "Turn tail" , "head for the hills" , "Run quickly away" , "Abscond" .)