Monaco is a part of the Schengen Area; if you turn up on a boat at Monaco (assuming you're allowed to dock), you'll be inspected by both French and Monégasque immigration authorities and issued both a Schengen visa from France and a Monégasque passport stamp. Monaco does not issue Schengen visas, but neither does Liechtenstein.
Switzerland has so many agreements with EU that it's more inside than outside IMO. They just prefer to keep each subject separate rather than joining EU or EEA.