Indulge in sport, very noisily, in a boat (5)
I believe the answer is:
skiff
'boat' is the definition.
(I know that skiff is a type of boat)
'indulge in sport very noisily' is the wordplay.
I cannot quite see how this works, but
'very noisily' could be 'ff' and 'ff' is found in the answer.
The remaining letters 'ski' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'in a' acts as a link.
Can you help me to learn more?
(Other definitions for skiff that I've seen before include "Small rowing boat" , "Light rowing boat for one person" , "Small light boat" .)