Bring snacks like granola bars for when you are off the ship. The only portable snacks on board for the most part are apples and bananas. You are allowed to bring one bottle of wine per person.

You can generally bring a banana on a cruise ship if you are boarding at your home port (initial embarkation), provided it is for immediate consumption during the boarding process. However, most cruise lines—including Carnival, Royal Caribbean, and Norwegian—have strict policies against bringing perishable food, especially unsealed fresh produce, into the ship's cabin. This is primarily due to agricultural regulations and the risk of introducing pests or diseases into the ship's environment. The rules become much stricter when getting off the ship or returning from a port of call. It is strictly illegal to take fresh fruit, like a banana from the ship's buffet, into most ports (such as Mexico or the Caribbean) due to local agricultural laws. Many ports use sniffer dogs to detect fresh produce, and being caught with a single piece of fruit can result in fines of $300 to $500. For your own safety and to avoid legal trouble, it is best to stick to pre-packaged, factory-sealed snacks if you need to bring food on or off the vessel.