Port entry requirements

Passports not valid for at least 6 months beyond cruise dates will generally not get you on any CCL family ship; you will need BC and valid government issued photo ID with all names matching.

While you don't technically need the passport to travel on a closed loop cruise, you might need it for medical or other evacuation purposes.

So, you can get on the ship w/just a BC & DL, but if you don't have those and present a passport with less than 6 months remaining, you likely will be denied boarding.

Well, I just did a little more research on this, and it's really not clear. Carnival says they "highly recommend" traveling with a passport with at least 6 months validity, otherwise there may be a delay at debarkation. Possibly the same "delay" as experienced by those traveling without a passport.

From their web page:

"U.S. citizens may present a valid, unexpired U.S. passport when traveling via air, land or sea. Carnival highly recommends that all guests travel with a passport valid for at least six months beyond completion of travel."

They also say that no passport is required when cruising to Alaska, The Bahamas, Bermuda, Cozumel, New England and Canada, The Caribbean, Hawaii, and Baja, Mexico. Instead, an official birth certificate and gov't issued ID can be used at embarkation.

The issue with a soon-to-expire passport (and possibly a birth certificate/ID pair) might be in the case where you miss the ship either at the home port, or one of the ports of call, and need to fly to the next port. I suppose it would depend upon the airline and/or local authorities as to whether a short-dated passport would be accepted.

I'm guessing that cruising without a passport isn't a huge problem, since I see many, many people in the "No Passport" line at debarkation. These would primarily be US Citizens traveling with a naturalization certificate or birth certificate, or people with a non-US passport (e.g. Canada), or US permanent residents with a green card.

I would suggest using your current passport at check-in, but having your birth certificate and driver's license as a backup if requested. It would be interesting to know if your currently valid but soon to be expired passport will be accepted by Carnival staff at check-in.

Here are a couple of useful pages from Carnival's website:

https://www.carnival.com/help?topicid=3409

https://www.carnival.com/awaywego/cruising-fun/how-to-plan/places-to-cruise-without-a-passport

If sailing on Carnival, your passport cannot be usded if it's within 6 months. We had friends traveling to Mexico (not cruising) and they could still use their passports that expired within a month. It's wise to have the backup, certified birth certificate. Maybe they will let you, but I certainly wouldn't count on it.

Umm I seem to recall seeing something about a passport cannot be used if it is within 6 months of expiration. You might want to look into that a bit closer.

I don't think you'll have a problem. Usually, when applying for a visa (sticker or stamp that allows entry into another country) your passport needs to have validity at least 6 months past the entry date. In the case of a cruise where visas aren't required, I don't think there's any requirement for passport validity beyond your cruise. In any event, if you're still worried, just bring your birth certificate and gov't issued ID which can be used in lieu of a passport for both embarkation and debarkation.