OK in the main, others way different (9)
I believe the answer is:
seaworthy
'ok in the main' is the definition.
(main can mean sea)
'others way different' is the wordplay.
'different' is an anagram indicator.
'others'+'way'='othersway'
'othersway' anagrammed gives 'SEAWORTHY'.
(Other definitions for seaworthy that I've seen before include "Safe to sail in" , "(Of ship) fit to set sail" , "Able to endure stormy weather" , "In a fit state for ocean voyage" .)