Love being in club on pine vessel (8)
I believe the answer is:
longboat
'vessel' is the definition.
(longboat is a kind of vessel)
'love being in club on pine' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'being in' means one lot of letters goes inside another.
'club' becomes 'bat' (as in sporting equipment).
'on' says to put letters next to each other.
'pine' becomes 'long' (to pine for something is to long for it).
'o' inserted into 'bat' is 'boat'.
'boat' after 'long' is 'LONGBOAT'.
(Other definitions for longboat that I've seen before include "Vessel used by the Vikings" , "Viking ship" , "Viking transport" , "Viking warship" , "one getting a row?" .)