They're far from the main sanctions to follow call for peace (8)
I believe the answer is:
shallows
'they're far from the main' is the definition.
The definition suggests an adverb but the answer is not.
'sanctions to follow call for peace' is the wordplay.
'sanctions' becomes 'allows' (I've seen this in another clue).
'to follow' means one lot of letters go next to another (some letters go after or follow others).
'call for peace' becomes 'sh' ('sh!' is a request for silence).
'allows' after 'sh' is 'SHALLOWS'.
Can you help me to learn more?
(Other definitions for shallows that I've seen before include "Safest part of river" , "Not-deep areas in body of water" , "Area of a river where the water is not deep" .)