See dry rot ruined vessel (9)
I believe the answer is:
destroyer
'vessel' is the definition.
(destroyer is a kind of vessel)
'see dry rot ruined' is the wordplay.
'ruined' is an anagram indicator.
'see'+'dry'+'rot'='seedryrot'
'seedryrot' is an anagram of 'DESTROYER'.
(Other definitions for destroyer that I've seen before include "One who wrecks" , "killer" , "likely to break down" , "heavily armed warship" , "Small, fast warship" .)