[bluGill]

It is a mix. Resupply depends on many factors. Remember ships are stopping at different ports - and often different countries every day (except for cross ocean cruises which of course which don't stop). Thus they look into local taxes, availability, and such. Meals are planned which means they know what they need - but also means they can look at what will be available. They have the ability to load at any port. If they can get X cheap at some port they will buy it there. Thus if they can contract a local farmer to supply something cheap in one port they will. If shipping means some non-local food is cheaper in one port than another they will buy at the cheaper one. If labor is cheaper in one port they will try to use more of that labor.

Supply management is important to a cruise line. They are very good at getting the best prices. They take advantage of the ship moving to get the best prices.