Disagreement with info held by frogman about middle of ocean (10)
I believe the answer is:
divergence
'disagreement' is the definition.
(I know that disagreement can be written as divergence)
'info held by frogman about middle of ocean' is the wordplay.
'info' becomes 'gen' (informal term for information).
'held by' means one lot of letters goes inside another.
'frogman' becomes 'diver' (synonyms).
'about' becomes 'c' (circa).
'middle of' indicates the central letters.
The centre of 'ocean' is 'e'.
'diver'+'c'='diverc'
'gen' placed inside 'diverc' is 'divergenc'.
'divergenc'+'e'='DIVERGENCE'
'with' acts as a link.
(Other definitions for divergence that I've seen before include "A moving apart" , "departure" , "being different" .)