Net diver has turned upside down (8)
I believe the answer is:
inverted
'turned upside down' is the definition.
('invert' can be a synonym of 'turn upside down')
'net diver' is the wordplay.
'net diver' can be anagrammed to 'INVERTED'.
But, I am not sure how this is indicated.
'has' is the link.
Can you help me to learn more?
(Other definitions for inverted that I've seen before include "Upturned" , "Turned upside down" , "Upside-down" .)