How many years are you willing to spend in a Guatemalan prison so you can smoke a joint? Even though the authorities might not ordinarily do a search of every nook and cranny when a middle-aged husband and wife enter the country, they might do a more thorough search of a boat sailed by a young person, because he might fit the "profile" of a person who would be in possession of drugs. They might do an exhaustive search of your boat just because they want to make a "statement" that they are co-operating in the war on drugs. Regardless of what their usual or customary practices might have been, you can''t know what instructions their supervisor has given them for that day.
My drug of choice is Scotch, but I''d leave it at home if there was any chance I''d have to spend time in a foreign prison for having it.