Cathy's new boats (6)
I believe the answer is:
yachts
'boats' is the definition.
(yachting is a kind of boating)
'cathy's new' is the wordplay.
'new' indicates an anagram.
'cathys' with letters rearranged gives 'YACHTS'.
(Other definitions for yachts that I've seen before include "Sailing vessels" , "Expensive cruising vessels" , "Craft for 6 dn" , "Pleasure craft" , "Racing or cruising boats" .)