Drug found in fishing-vessel (5)
I believe the answer is:
smack
This could be a double definition.
'drug found in fishing' is the first definition.
'smack' can be an answer for 'drug' (I've seen this before). I am not sure about the 'found in fishing' bit.
'vessel' is the second definition.
(smack is a kind of vessel)
Can you help me to learn more?
(Other definitions for smack that I've seen before include "Hit - fishing vessel" , "Heroin (sl.)" , "box" , "Fishing-boat, hit" , "Hit - drug" .)