I'd been driving for nearly two hours from Pisa, near Florence, about three hundred kilometers already behind me, when I stopped for a coffee on the way to Naples. I went to pay. I opened my wallet, and my stomach dropped: my ID wasn't there. All I found in its place was a receipt from the last hotel.

I'll tell you how that story ended further down. But first, let's get to what you actually came here for.

Short answer: it has nothing to do with how many cruises you've done. Doesn't matter if it's your first or your thirteenth. It comes down to three things — your nationality, the type of trip, and the destination. A cruise, in this respect, works exactly like a flight.

If you're not sure, assume you need a passport — it's valid almost everywhere, which a national ID card usually isn't. Some regional blocs let their own citizens travel between member countries with just a national ID (EU citizens moving within the EU, for example), but the moment your itinerary leaves that bloc, or you're not a citizen of it, that stops applying. And if your nationality requires a visa for a given country, that depends entirely on your passport — not mine, not the person's next to you on the ship. Visa rules and processing times vary enormously by nationality. My only real recommendation: check it yourself, every time, on your own government's official travel site before you book anything. Not on a travel blog. Not even this one.

Yes. My favorite itinerary ever — I'll tell you about it another day — sailed through Turkey, so I get asked about this a lot. For most European passport holders today, entering Turkey isn't especially complicated: it's handled right at the port's customs checkpoint. But they do ask for and check your passport — a national ID card won't do. Rules like this change over time, so double-check before your own cruise too: don't assume what worked for me will work the same for you.

Picking up where I left off. It happened near Pisa, in the Florence area, on a work trip for my previous company. One night at the hotel, like most nights back then. At check-in, the front desk guy said, "leave it with me, I'll register it tonight and give it back tomorrow" — a completely normal procedure, so I handed it over without a second thought. The next morning I left in a rush, there'd already been a shift change at the desk, and neither they remembered to return it nor I remembered to ask for it.

The real problem: I was doing that trip with only my ID, no passport on me. And I had a flight three days later out of Naples. So I had to stop everything, turn the car around, drive all the way back to Pisa, pick up my ID, and head south again. Six hundred extra kilometers for a piece of paper that — had I been carrying my passport — I'd have avoided completely: the hotel could have just mailed it to me back home, no need to move the car at all.

Ever since, I carry both documents, even when the destination doesn't require it. Because if one fails, you have the other. And "failing" happens more than you'd think: losing your documents mid-cruise can complicate things as small as banking on board, not just going ashore.

This one didn't happen to me — it happened to some travel companions of mine. They were in the middle of renewing their residency permit — already approved, but without the final document yet, only certification letters from the Spanish police. Those letters meant nothing to the Italian authorities. We argued with the cruise line, back and forth, but the ship's own passport and customs officer wasn't willing to take the risk: the next port was Croatia, and if that person got denied entry there, the fine would land on the cruise line, not just cause a problem for the passenger.

It's not that cruise lines are being difficult for the sake of it. They answer to the authorities of every country they visit, and that affects you directly.

You have up to a month before the cruise to do this, and it's what confirms to the cruise line that you're actually showing up. A lot of people leave it for the very last moment, or forget it entirely.

Someone gets off the ship at a port to explore the city, carrying nothing but their cruise card — no ID, no passport. Local authorities often let it slide, sure, but that card is not a valid form of identification. If something happens to you on land, you're effectively undocumented. Simple as that.

My advice: carry duplicate documentation if you can — leave one set in your cabin, take the other ashore with you. I know of cases where people had their documents stolen along with their boarding card right at the port, and because the other set was safely in the cabin, a family member was able to go retrieve it and use it to get a replacement card issued. Without that, it would have been a much bigger mess.

You'll need a signed authorization from the other parent allowing the trip. It's the law, and it can be requested at any checkpoint. If you're unsure about your specific case, ask your national police directly before you leave — it's free, and it's the most reliable source you'll find.

Duplicate documentation, always on you when you go ashore, and if you're traveling with minors, sort the paperwork before you leave home, not at the port. Everything else is just details.

Since Pisa, I don't travel anywhere without my passport. Not to the Mediterranean, not around the corner if I could help it. I wish I'd learned that lesson without the six hundred extra kilometers.

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