Keep the buoy on your right or starboard side.
They should be passed on your starboard side.
port side(Left)
Keep the buoy on your port (left) side.
I think you should----Keep the buoy on your port (left) side.
When passing a buoy marked with the number 4 and a flashing red light, you should keep the buoy on your port (left) side. This indicates that you are in a channel where the right side is marked with green buoys. Always maintain a safe distance from the buoy and be aware of any potential hazards in the water.
Pass the buoy so that it is to your right (red right returning).
pass on port (left) side
go around on either side
Pass to your port side headed to sea, starboard returning (red-right-returning).
Since this is a Green Lighted Buoy sighted while approaching a harbour,this is a Lateral port hand side mark, IALA region B. To keep this buoy on your port side while travelling upstream.
They pass Port To Port side