Feathered, it may skim the water surface (3)
I believe the answer is:
oar
'surface' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for oar that I've seen before include "Bladed pole" , "It ends in blade" , "Use it to move a boat" , "Rowing device" , "Rower's flat blade" .)