Adding to list long liner that's wrecked (9)
I believe the answer is:
enrolling
'adding to list' is the definition.
(I've seen this before)
'long liner that's wrecked' is the wordplay.
'that's wrecked' indicates an anagram.
'long'+'liner'='longliner'
'longliner' anagrammed gives 'ENROLLING'.
(Other definitions for enrolling that I've seen before include "listing!" , "Registering officially" , "Adding to list" .)