Pass by one rig at sea (6)
I believe the answer is:
ignore
'pass by' is the definition.
(I've seen this before)
'one rig at sea' is the wordplay.
'at sea' indicates an anagram.
'one'+'rig'='onerig'
'onerig' is an anagram of 'IGNORE'.
(Other definitions for ignore that I've seen before include "Dismiss" , "Forget" , "Pay no attention to, disregard" , "Intentionally disregard" , "Spurn" .)