Fetch naval leader in ship (5)
I believe the answer is:
bring
'fetch' is the definition.
(I know that fetch can be written as bring)
'naval leader in ship' is the wordplay.
'leader' suggests taking the first letters.
'in' indicates putting letters inside.
'ship' becomes 'brig' (I've seen this before).
The initial letter of 'naval' is 'n'.
'n' going within 'brig' is 'BRING'.
(Other definitions for bring that I've seen before include "Come along with" , "Carry (to a place)" , "Get" , "Fetch; cause to come" , "Escort" .)