We took our 8 month old daughter on her first cruise last year, and just booked her second cruise for this year. She absolutely loved it and it was such a great trip! Her last trip was on Carnival, and our upcoming trip is on Royal Caribbean. I get so excited thinking about the status for each cruise line that she'll have by the time she's sailing off into the sunset for retirement since she's starting so young. The cost to add a baby to our room actually wasn't that much. Most cruises have a discount for the 3rd passenger in a room, and sometimes you can catch a kids-sale-free promotion to offset the cost of your room.
Honestly the hardest part about cruising with a baby is that we've been spoiled by daycare and used to just keeping her all day for the weekends only, so we forgot how exhausting it was to be on parent duty all day. Traveling with a baby wasn't much different than being at home with her, but that's probably because we tried to be as thoughtful as we could with what we brought with us.
Baby passports for cruises
Depending on your itinerary, you might not need a passport for your baby. You can call customer service for your cruise and confirm if a birth certificate is enough for your stops. However, I HIGHLY recommend you get your baby a passport if you have the time before your cruise. Embarkation and disembarkation days go SIGNIFCANTLY faster if everyone has a passport. I'm talking the difference between security being under 30 minutes if you all have a passport, and over 2 hours if someone has a birth certificate.
Baby age requirements for cruises
For most cruises, the general rule of thumb is that a baby has to be at least 6 months old by the first day of the cruise. In general, cruises that have two back-to-back sea days in a row will require a baby to be one year old for the cruise. Other than that, there's not a lot of restrictions for cruising with your baby, and most cruises are very welcoming to babies.
Baby activities on ships
One thing to keep in mind is that most cruises won't allow drop-off for children under 3 in their free kids centers. Many have paid baby-sitting hours in the evenings where you can take your baby to the kids center for a baby-free dinner and show, most have paid baby-sitting hours during port days where you can go ashore without your baby, and it's common for the kids center to have organized activities for parents to bring their babies to and stay and play with them in the kids center. I recommend you go to the kids center first thing when you get on the ship to see what is and isn't offered, the times, and the prices so you can plan your trip around that. Personally, we took our daughter with us at each stop because we wanted her to get the full travel experience. We didn't do any "excursions" other than reserving clamshells ahead of time when available, and spent each stop on the beach or walking around the port.
Diaper changes on ships
When we went on our trip, she was sitting up and just starting to crawl here and there. She had also just begun baby-led weaning, but mostly still preferred bottles. They had high chairs in the dining area, and the wait staff were always so sweet to try to think of different foods my daughter might like and bring out samples for her to try out. On the Carnival Conquest, there weren't changing tables in any bathrooms that I went in to on the ship, so plan on going back to your stateroom to change any dirty diapers. The gift shop on the Carnival Conquest had like 3 packs of Size 2 diapers, wipes, and no formula, so I would plan to have more packed then you need. Most likely, if you need to you can find items at the port, but it might not be the brand your baby is used to and it will definitely be overpriced.
Sleeping

You're going to want to bring your own crib sheets. I recommend you bring 2 sets so that you can swap them out if your baby gets one set dirty. Royal Caribbean provides you with a pack-n-play, and at least on the Carnival Conquest we were offered a metal rollaway crib, but neither provide sheets. Bring crib sheets that are colorful or have a pattern and avoid plain white sheets so that your sheets don't get mistaken for the cruise's bedding and get taken away by housekeeping. Having your own sheets is actually nice because you can wash it with your own detergent and know that 1) it's free from any harsh chemicals or perfumes that your baby's sensitive skin might not be used to and 2) it will smell like home and can be comforting to your baby being in a strange place. I knew ahead of time that I didn't want to use Carnival's metal crib, so we actually brought our own travel play yard that my daughter is used to sleeping in and had mesh sides so she wouldn't hurt herself rolling around into the sides. This travel crib is absolutely amazing! It is SO lightweight and SO easy to put together. One of the reasons why I didn't want the rollaway crib in our room is because I wanted the flexibility to easily tear down my daughter's bed to give us more floor room for her to crawl around while we were getting ready. We also got a mesh blackout cover to fit over her bed so that we could keep the lights on while she slept. At night, my favorite travel sound machine has a built-in night light so we could see if we had to get up to feed her.
Bottle feeds while traveling
Bottle feeding my daughter on the cruise was actually simple. We only brought a travel bottle bag filled with her usual bottles (labeled with her name, in case we lost one), an insulated water bottle to hold just her water (we ordered filtered water through the ship for I think $2 a gallon?), and we brought the big tubs of formula in our suitcase and then just measured out the formula into a travel formula dispenser. This was all we needed and we were able to make her bottles when we were up on deck or out on shore at the port, easy peasy.
Strollers on cruises
Leaving our stateroom actually didn't require that much effort. We had the GB pockit travel stroller which was perfect because we could fold it up and store it under our bed when we didn't need it, and it was lightweight enough that my husband could carry the stroller with our daughter in it when the elevators were taking too long. Out at port this stroller worked great because it has a good-sized canopy to keep the sun off her, and the seat reclined so she could easily take stroller naps while we walked around. We brought a stroller fan for our daughter to keep her cool.
Although we could have brought our normal stroller, the Uppababy Vista, from home, and we did see a few families having big strollers like this, I would avoid them if you can. There's a good chance that the normal-sized stroller will be wider than the cabin door, making it really difficult to get your stroller in and out of your room, and you can't leave your stroller in the hallway. Even if you can get it in your room, you likely won't have anywhere to put a stroller that doesn't fold up. Remember, cruise rooms are much smaller than hotel rooms to begin with, and what little free space you'll have in your room will likely be taken up by the baby's bed. A cheaper alternative to the GB pockit is the Summer Infant 3D lite stroller, which is like an upgraded umbrella stroller because it can recline and has storage. If you want to go the cheapest route, make sure you at least get an umbrella stroller with a canopy to keep you kid shaded.
Travel items for cruises
The bottle bag could hold bottles and formula and could fit with the water bottle in the basket under the seat. I didn't even bring a diaper bag, just a diaper fanny pack loaded with wipes, diapers, a paci (on a paci strap with her name on it in case it got lost), and a burp cloth that can convert into a bib. Yes, even at port, I didn't take her diaper bag off with us! I actually never used her diaper bag once we got on the ship. When we got off the ship at port, I just added a little stroller caddy on the handles so that we could have a place to store our drinks and things within reach. I also kept a little hand-held fan in our stroller caddy to fan off our daughter (or us!) on hot days, I just made sure to choose a fan that had the blades covered so she couldn't hurt herself on it.
Beach items

For the beach, I was a little less minimalist and a little more overboard mom. I packed this travel beach bag that folds up so tiny, yet is HUGE when you unfold it, and is completely mesh so you're not brining a ton of sand and water back with you. In it, I packed a simple baby float for the water and this little portable pool with shade and also a travel beach toys set with a collapsible beach bucket. What was nice with the baby pool is that found chairs away from the crowds and so we were able to dig her a little hole in the sand so that she could play in the water while shaded and away from drunk people and kids getting in her way and splashing her because there's nothing worse than saltwater in a baby's eyes (after trial and error, my husband recommends to pack a folding travel shovel to easily dig the hole and to ask a bartender for an empty beer bucket to fill up the pool with ocean water). I chose to put our daughter in a full-body swimsuit because it's easier to keep her covered than to constantly reapply sunscreen. And I know that people say you can air dry a disposable swim diaper and re-use them (swim diapers only hold poop, not pee), but I've found that re-usable swim diapers are easier to take on and off, dry faster, and hold up better throughout the day. What worked for our daughter is getting off the boat and going into the water to play first thing, then changing her into a dry diaper for lunch and nap while her swimsuit and swim diaper dried in the sun, and then either changing her back into her swim outfit for more playtime, before going back into a dry diaper and dry clothes to get on the boat. One thing we found out the hard way is that because swim diapers don't hold pee, if you put your baby in a swim diaper while you're getting dressed on the ship and then your baby pees in the time it takes you to get off the ship, your baby will pee through their swim diaper, just FYI.
Room entertainment
To keep our baby entertained back on the ship, we brought suction cup spinner toys to stick to doors for her to sit on the floor and play with while we got dressed. For meals, we had a suction cup toy holder loaded with her favorite toys that we could stick to her high chair to keep her busy while we ate. Your cruise won't let your baby into the ship pool if they're still in a swim diaper, but some have splash pads that will allow all ages to play on. For us, we brought a mini baby pool for her to play with. You can either set this up in the shower, or if you have a balcony then you can set it up out there. I took an empty trashcan and filled it with warm water to fill up her pool. We had this tiny travel air pump which made inflating and deflating the pool take about a minute, so I didn't mind setting this up every day for her and then taking it down at night. I brought some cheap foam bath letters for her to play with in the pool, and she loved it!
Baby medicine at sea
Adding a baby to your cruise doesn't necessarily wreck havoc on your room. We had disposable diaper pails that we would fill up throughout the day and then the room keepers would toss it each day. We set up a shoe organizer filled with diapers, wipes, pacifiers, medicine, and baby clothes. My biggest fear was that my daughter would teeth or get sick on this trip and wake up our neighbors screaming, so I packed travel acetaminophen and teething drops just in case. I did pack travel laundry detergent and I'm glad I did because we ran out of clean burp cloths quicker than I anticipated so I did a quick load of laundry in the bathroom sink.
Baby cruise outfits
For packing, I would recommend one burp cloth per day of the trip plus a spare. We just brought one swimsuit per day, 2 reusable swim diapers, one pack of disposable swim diapers, pj's and socks for each night, a romper for each day, and one dress for the formal night. We calculated how many diapers she wore each day, and packed that amount plus 2 extra days' worth, and did 1 package of wipes plus a travel set of wipes for the fanny pack. We did the same thing to calculate how much formula we needed.
How can getting
a passport for my
baby enhance the cruise embarkation process?
What age restrictions should I be aware of when cruising with a baby? Why
is it important to bring my own crib sheets on a cruise? What are practical
tips for bottle feeding my baby during the cruise? How can I make leaving the
stateroom with a baby effortless? What are creative ways to keep my baby
entertained on a cruise ship? How can I manage baby essentials in the stateroom
without disrupting neighbors? What beach essentials should I pack for a cruise
with my baby? How do I calculate diaper and formula needs for my baby during
the cruise? What's the best way to handle potential diaper emergencies on a
cruise?