Sea god made short voyage to northern capital (6)
I believe the answer is:
triton
'sea god' is the definition.
(figure of Greek myth)
'short voyage to northern capital' is the wordplay.
'short' means to remove the last letter.
'voyage' becomes 'trip' (I've seen this in another clue).
'to northern' says the letters should be written backwards (in a down clue, letters go up or 'north').
'capital' becomes 'not' (I can't explain this - if you can you should believe this answer much more).
'not' in reverse letter order is 'ton'.
'trip' with its final letter taken off is 'tri'.
'tri'+'ton'='TRITON'
'made' acts as a link.
Can you help me to learn more?
(Other definitions for triton that I've seen before include "conch-blowing deity" , "Greek minor sea-god with trident, fish-tail and shell trumpet" , "heavenly conch-blower" , "Moon" , "Greek sea-god like man with fish's tail, trident and shelltrumpet" .)