Bad horse at sea quite near coast (8)
I believe the answer is:
offshore
'bad horse at sea quite near coast' is the definition.
I can't tell whether this definition defines the answer.
'bad horse at sea' is the wordplay.
'bad' becomes 'off' (I've seen this before).
'at sea' is an anagram indicator.
'horse' with letters rearranged gives 'shore'.
'off'+'shore'='OFFSHORE'
Can you help me to learn more?
(Other definitions for offshore that I've seen before include "Out to sea, away from land" , "Out of tax jurisdiction" , "avoiding tax" , "confined to coastal waters" , "In the main" .)