When it comes to cruises, the top deck pool is often a highlight for most passengers, being the ideal spot to soak up the sunshine and take in the ocean views. (Not to mention it's often where you'll also find water slides and splash zones for the kids!)
However, there's one little-known rule that almost every single cruise line has in place including the likes of Royal Caribbean and MSC Cruises; and it can mean that some families won't be able to use the pool.
If you're travelling with kids, it's important to check the guidelines for your cruise but most cruise lines require that any child who wants to go into the main pool be potty trained. If they're still in nappies (including swim nappies), then they'll be banned from the main pool.

READ MORE: Full list of new cruise ships for 2026 including Royal Caribbean and TUI
The main reason is that if a little one has a leaky nappy and does their business in the water, then for health and safety reasons the pool needs to be drained, cleaned and then refilled. This takes up a lot of time, so the pool is then left out of action for other passengers. Not only will that be frustrating, but it also means that other areas of the ship then face getting crowded because people head to other entertainment venues while they wait.
MSC Cruises states that "for hygienic reasons, babies in nappies are not allowed in the water", while Royal Caribbean says that "children in diapers, swim diapers, pull-ups, or who are not completely toilet trained are not allowed in the pools, and whirlpools, or H2O Zone".
For cruise lines that are sailing from the USA, it's a Public Health requirement that children who are toilet trained can go into the swimming pools and areas such as spas and hot tubs on cruise ships.
READ MORE: Europe's 'safest city' has beautiful Old Town, hidden beach and Game of Thrones link
READ MORE: Clever way cruise ships use 'blue mind effect' to keep passengers happy onboard
The good news is that babies and toddlers don't need to miss out on all of the fun. Most cruise lines will still let families bring them into the pool area as long as they don't go in the water - and plenty of cruise ships have dedicated splash zones for little ones where they can play and enjoy the area with their parents.
For example, Disney Cruise Line explains on its website that kids who aren't toilet trained are "welcome to enjoy the water play areas on board each ship while wearing a swim diaper". (Although it's worth noting that swim nappies aren't allowed on hot tubs, spas, or waterslides on their ships). Meanwhile some of the ships in the Royal Caribbean fleet have a Baby Splash area that are "only for use of children that are in diapers".
Cruise lines remain tight-lipped about what happens if someone chooses to break the rule. Usually, lifeguards and crew members will keep an eye out and stop you from going in the water with your baby - and if you're a repeat offender, they could choose to ban you from the pool altogether.
Of course parents and older kids can still continue to use the main pool - and if you have a little one with you, it's always worth looking at the ship's kids' club offerings, if you wanted to have some time to yourself to make the most of the poolside loungers too!
Want to join our cruise community? Sign up to Anchors Away for a weekly dose of cruise news, sneak peeks inside ships and travel tips we think you'll love.
You may also like
'I will have to do all the talking': Trump hints at central role in Russia-Ukraine talks; says Zelenskyy, Putin hate each other
I'm A Celeb book Carol Thatcher for controversial TV return after being cancelled
Judy Finnigan and Richard Madeley pictured in rare family photos with their granddaughter
Zoe Ball shares fears for children as she makes painful family realisation
Rajasthan bureaucratic reshuffle: 222 RAS officers transferred, Mohan Dan Ratnu appointed OSD to CM Sharma