Boats at sea to get on, and wreck (8)
I believe the answer is:
sabotage
'wreck' is the definition.
(I've seen this before)
'boats at sea to get on' is the wordplay.
'at sea' indicates anagramming the letters.
'to get on' becomes 'age' ('age' can be a synonym of 'get on').
'boats' with letters rearranged gives 'sabot'.
'sabot'+'age'='SABOTAGE'
'and' is the link.
(Other definitions for sabotage that I've seen before include "cripple" , "Got a base (anag.)" , "Subversion by inflicting damage" , "Deliberate damage (eg, in wartime)" , "Deliberately destroy" .)