Cathy's new bloke is a sailor (9)
I believe the answer is:
yachtsman
'sailor' is the definition.
(yachtsman is a kind of sailor)
'cathy's new bloke' is the wordplay.
'new' is an anagram indicator.
'bloke' becomes 'man' (I've seen this in other clues).
'cathys' is an anagram of 'yachts'.
'yachts'+'man'='YACHTSMAN'
'is a' acts as a link.
(Other definitions for yachtsman that I've seen before include "(Recreational) sailor" , "Description of Chichester" , "crafty person" , "Sir Francis Chichester, perhaps" , "Member of sailing crew" .)