Some enormous keg going in part of boat (5)
I believe the answer is:
skegg
'part of boat' is the definition.
(skegg is a part of some boats)
'some enormous keg going' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'SKEGG' is hidden in the letters of 'enormous keg going'.
'in' is the link.
(Other definitions for skegg that I've seen before include "sailboard stabilizer" , "surfboard stabiliser" .)