US soldier in ocean capsized, getting protection (5)
I believe the answer is:
aegis
'protection' is the definition.
('aegis' can be a synonym of 'protection')
'us soldier in ocean capsized' is the wordplay.
'us soldier' becomes 'gi' (I've seen this in other clues).
'in' means one lot of letters goes inside another.
'ocean' becomes 'sea' ('sea' can be a synonym of 'ocean').
'capsized' is a reversal indicator.
'sea' back-to-front is 'aes'.
'gi' inserted into 'aes' is 'AEGIS'.
'getting' is the link.
(Other definitions for aegis that I've seen before include "Advocacy" , "Backing or support" , "shelter" , "Protection or sponsorship" , "Custody" .)