Set off again in leisure craft (7)
I believe the answer is:
restart
'set off again' is the definition.
('start' can be a synonym for 'set off' so perhaps 'restart' is OK for 'set off again')
'leisure craft' is the wordplay.
'leisure' becomes 'rest' (I've seen this before).
'craft' becomes 'art' (I've seen this before).
'rest'+'art'='RESTART'
'in' acts as a link.
(Other definitions for restart that I've seen before include "begin afresh" , "launch again" , "Commence again" , "Begin anew" , "Resume" .)