Prize in harbour recalled happily after vacation (6)
I believe the answer is:
trophy
'prize' is the definition.
('trophy' can be a synonym of 'prize')
'harbour recalled happily after vacation' is the wordplay.
'harbour' becomes 'port' (I've seen this before).
'recalled' says the letters should be written backwards.
'after vacation' suggests removing the centre (the inside letters must vacate).
'happily' with its centre removed is 'hy'.
'port' in reverse letter order is 'trop'.
'trop'+'hy'='TROPHY'
'in' acts as a link.
(Other definitions for trophy that I've seen before include "Prize, eg cup" , "Prize or token of victory" , "leading award" , "Prize symbolising victory" , "Laurels" .)