Prepare to publish current returns (4)
I believe the answer is:
edit
'prepare to publish' is the definition.
(to prepare material for publication)
'current returns' is the wordplay.
'current' becomes 'tide' (sea currents).
'returns' shows that the letters should be reversed in order.
'tide' in reverse letter order is 'EDIT'.
(Other definitions for edit that I've seen before include "be a bookmaker" , "Redact, perhaps" , "Make textual changes" , "Revise for publication" , "Tide (anag.)" .)