Originally Posted by granite
In reference to bringing snacks off the ship: Many people have to have specific 'between meal' snacks for health reasons (such as pre-diabetes or diabetes), and hesitate to eat food purchased in foreign ports - especially fruit. Hence, pieces of fruit or nuts/crackers are taken from the ship.
When you bring fruit into a foreign country, you may be not realize it, but you brining a disease or bug that are not native to the port/country. Several years ago an unknowing cargo ship from Asia imported the asian long horned beetle into Canada. This beetle has no known predators in Canada and it's now wiped out entire forests in the Canadian Rockies.