Trouble with sailors in grand decking (8)
I believe the answer is:
adorning
'decking' is the definition.
(adorn can mean to deck or decorate)
'trouble with sailors in grand' is the wordplay.
'trouble' becomes 'ado' (both can mean bother or commotion).
'with' says to put letters next to each other.
'sailors' becomes 'RN' (abbreviation for Royal Navy).
'grand' becomes 'g' (G is short for grand as in a thousand).
'ado'+'rn'+'in'+'g'='ADORNING'
(Other definitions for adorning that I've seen before include "Decorating with ornaments" , "decking" , "Decorating, embellishing" .)