Cathy wrecked boat (5)
I believe the answer is:
yacht
'boat' is the definition.
(I know that yacht is a more specific form of the action boat)
'cathy wrecked' is the wordplay.
'wrecked' is an anagram indicator.
'cathy' anagrammed gives 'YACHT'.
(Other definitions for yacht that I've seen before include "Light sailing-vessel for sport" , "Sailing or motor vessel for cruising or racing" , "Light sailing vessel" , "Light, fast sailing-vessel" , "Sailboat" .)