Captain beginning to skin smoked fish (7)
I believe the answer is:
skipper
'captain' is the definition.
(I know that skipper is a type of captain)
'beginning to skin smoked fish' is the wordplay.
'beginning to' says to take the initial letters.
'smoked fish' becomes 'kipper' (I've seen this before).
The initial letter of 'skin' is 's'.
's'+'kipper'='SKIPPER'
(Other definitions for skipper that I've seen before include "Ship's captain (colloq.)" , "sleep in outhouse" , "Captain - one using a rope" , "Senior pilot" , "One who misses" .)