Hard-nosed paper probes impact at sea (9)
I believe the answer is:
pragmatic
'hard-nosed' is the definition.
('pragmatic' can be a synonym of 'hard-nosed')
'paper probes impact at sea' is the wordplay.
'paper' becomes 'rag' (rag is a kind of paper**).
'probes' indicates putting letters inside.
'at sea' is an anagram indicator.
'impact' with letters rearranged gives 'pmatic'.
'rag' going within 'pmatic' is 'PRAGMATIC'.
(Other definitions for pragmatic that I've seen before include "Practical" , "Matter-of-fact" , "Down-to-earth" , "for best results?" , "Realistic" .)