Story about harbour (6)
I believe the answer is:
report
'story' is the definition.
(synonyms)
'about harbour' is the wordplay.
'about' becomes 're' (common abbreviation for 'with reference to').
'harbour' becomes 'port' (I've seen this before).
're'+'port'='REPORT'
(Other definitions for report that I've seen before include "Formal document" , "Bulletin" , "Announce; rumour" , "Announce; gunshot" , "A crack" .)