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'.
However, I'm not clear 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" .)