Potty-Training and Swimming Pools
While most cruise ships are non-US, they still follow United States Public Health Service guidelines. This means no diapered kids in pools, for sanitary reasons.
Yes, some makers will sell you "swimming pool diapers" that claim to hold in body waste. However, studies have shown that these types of diapers do not always do an exceptional job of keeping the waste from entering the water. Since cruise ships hold hundreds, if not thousands of passengers, an outbreak of a disease can prove disastrous.
Many ships offer a children's wading area where kids can get wet without contaminating a sitting water supply. It's important to be very honest with the state of your child's potty training. If your child still has accidents, you do not want a lapse to cause a ship-wide sickness.
Also, it's unfair to yell at a child for simply not being mature enough to "hold it in". Childrens' bodies mature at different rates, and you can't force a body to grow up more quickly. In fact, most parents already complain that their kids grow up too quickly and try to act too mature for their age.
So watch your child for a month before the cruise, and if the child's ready for a pool, that's fine! If you're child isn't ready yet, that's fine too. There'll probably be plenty of beaches for you to splash in at the ports, and the boat will be chock-full of entertainment to keep you busy on board.
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