Relaxing novel read on motor yacht (6)
I believe the answer is:
dreamy
'relaxing' is the definition.
(thesaurus)
'novel read on motor yacht' is the wordplay.
'novel' indicates an anagram (letters in a new or novel order).
'on' says to put letters next to each other.
'motor yacht' becomes 'MY' (abbreviation for motor yacht).
'read' anagrammed gives 'drea'.
'drea'+'my'='DREAMY'
(Other definitions for dreamy that I've seen before include "delightful" , "wonderful" , "Fantastic" , "Gorgeous (informal)" , "My dear (anag.)" .)