Article bobbing around a water channel (8)
I believe the answer is:
tailrace
'article' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's an association between them I don't understand?
'bobbing around a water channel' is the wordplay.
'bobbing around' becomes 'tail' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a water channel' becomes 'race' (I've seen this in another clue).
'tail'+'race'='TAILRACE'
Can you help me to learn more?
(Other definitions for tailrace that I've seen before include "Watercourse" , "Fast-flowing water below a dam" .)