American soldier jumping into the ocean turns up for sponsorship (5)
I believe the answer is:
aegis
'sponsorship' is the definition.
(I've seen this before)
'american soldier jumping into the ocean turns up' is the wordplay.
'american soldier jumping' becomes 'gi' (I am not sure about this - if you are sure you should believe this answer much more).
'into' indicates putting letters inside.
'the ocean' becomes 'sea' ('sea' can be a synonym of 'ocean').
'turns up' says the letters should be written backwards.
'sea' in reverse letter order is 'aes'.
'gi' placed within 'aes' is 'AEGIS'.
'for' is the link.
Can you help me to learn more?
(Other definitions for aegis that I've seen before include "Protection or sponsorship" , "Friendly endorsement and guidance" , "Auspices" , "strong defence" , "Protection - patronage" .)