A bloke at sea covering East and West ultimately in yacht (8)
I believe the answer is:
keelboat
'ultimately in yacht' is the definition.
'keelboat' can be an answer for 'yacht' (I've seen this before). I am not certain of the 'ultimately in' bit.
'a bloke at sea covering east and west' is the wordplay.
'at sea' is an anagram indicator.
'covering' is an insertion indicator.
'east' becomes 'e' (abbreviation).
'and' says to put letters next to each other.
'west' becomes 'at' (I can't explain this - if you can you should give a lot more credence to this answer).
'bloke' with letters rearranged gives 'kelbo'.
'kelbo' going around 'e' is 'keelbo'.
'keelbo'+'at'='KEELBOAT'
Can you help me to learn more?
(Other definitions for keelboat that I've seen before include "yacht" , "vessel" .)