Is it possible to apply for a RE-ENTRY PERMIT at Koh Samui airport?
(Details: type of visa - 60 day, single entry tourist visa, nationality - american. Flight leaves Monday afternoon. If the answer to the above is a "no", is the other option to visit Koh Samui Immigration Office in the morning to apply for a re-entry permit?)
TLDR : Answer Summary
You cannot apply for a re-entry permit at Koh Samui airport as it is managed by a private company. Instead, you should visit the Koh Samui Immigration Office to apply for the permit, which can be done before your flight.