Vessel about to be wrecked (1-4)
I believe the answer is:
u-boat
'vessel' is the definition.
(I've seen this before)
'about to be wrecked' is the wordplay.
'to be wrecked' indicates an anagram.
'about' with letters rearranged gives 'U-BOAT'.
(Other definitions for u-boat that I've seen before include "Submersible warship armed with torpedoes" , "Take pool exercise" , "Sea vessel" , "About (anag)" , "German World War One or World War Two submarine" .)