Attention-seeker covering British sailors in battle? (6)
I believe the answer is:
arnhem
'battle?' is the definition.
(the Battle of Arnhem was a WW2 battle)
'attention-seeker covering british sailors' is the wordplay.
'attention seeker' becomes 'ahem' (cough used to attract attention).
'covering' means one lot of letters goes inside another.
'british sailors' becomes 'RN' (Royal Navy).
'ahem' placed around 'rn' is 'ARNHEM'.
'in' is the link.
(Other definitions for arnhem that I've seen before include "place noted for fighting" , "Dutch city" , "Netherlands scene of 1944 battle" , "Second World War battle" , "Location of battle" .)