Every cruise, I watch passengers get stopped before boarding at security for items they had no idea were banned.

Most people make an honest mistake by bringing things that aren't allowed onboard because they're a fire or security hazard. Most of these confiscated items don't get them in trouble, but it does result in a frustrating start to their vacation and the loss of the item until they return.
I know when I pack something for a cruise, I'm counting on having that item. So getting to taken away would put a dent in my plans.
While Royal Caribbean has a lengthy list of things you can't bring on a cruise, four are clearly the top items that seem to be accidentally brought onboard the most.
The most commonly confiscated item are irons and steamers

If you ever pass by the table of confiscated items to be picked up after a cruise is over, I can pretty much guarantee you'll see mostly clothing irons and steamers.
So many people mistakenly believe they can bring them on a cruise, but they'll be taken away as soon as they're spotted in your bags.
The reason why you can't bring clothing irons or steamers on a cruise is they are a fire hazard. If left unattended, they could start a fire and that's a risk Royal Caribbean won't take.

Fire is the most dangerous scenario for a cruise ship, so the ship's crew are extra vigilant when it comes to preventing fires.
Since irons and steamers aren't allowed, you'll have to figure out an alternative to getting wrinkles and creases out of your clothes.

There are a few options people rely on as a backup:
- Sending clothes out to be pressed onboard (extra cost)
- Bringing wrinkle release spray
- Leaving clothes in the bathroom while the shower runs to absorb the steam
- Rolling clothes in their suitcase
Each idea has its pros and cons, so you'll need to find the one that works best for your needs.
Beer or liquor isn't allowed to be brought onboard

A few cruise lines allow you to bring beer on embarkation day, but not Royal Caribbean. You cannot bring beer or liquor on your cruise.
In fact, the cruise line has gotten more stringent with checking for these items because people try to sneak it onboard.

You are allowed to bring wine or non-alcoholic drinks on your cruise. However, they might still search your bag if they see something in the bag scan that even resembles booze.
This rule is also enforced when you come back on the ship in a port of call. Cruisers like to buy bottles of liquor to bring home, but it will be taken from you until the cruise is over.
Power strips and other unapproved power adaptors are commonly taken from people

If clothing irons are the most confiscated item, then power strips are probably number two on the list.
You cannot bring a power strip or surge protector on a cruise. That's been a rule for many years, and it's because it's also a fire hazard.
But Royal Caribbean also prohibits bringing multi-plug outlets, which is a more recent change in policy.

The simplest way to know if your power adaptor is allowed on a Royal Caribbean ship is to make sure it only has one A/C outlet. The amount of USB outlets is irrelevant.
I recommend this universal power adaptor that works well for cruise ships and will help you if you end up traveling elsewhere around the world (Link contains affiliate link, which costs you nothing extra to use).
Appliances

As a general rule, you can't bring kitchen appliances on your ship either.
I've seen rice cookers, electric kettles, and coffee machines on the confiscated items table because people think they can save money and make certain foods in their cabin.
"Electrical items and electronic equipment not designed for personal grooming" aren't allowed.

If your ship sails from the UK, you can expect an electric tea kettle in your cabin.
Otherwise, you'll need to book a suite in order to have a coffee machine or electric kettle ready to use in your cabin that has been provided by the cruise line.






