Since a lightsaber is not a firearm and it’s not a real lightsaber - it can’t slice off an arm - I would put in my carryon (because it’s breakable) and take it with you. Keep it in the room.
When DCL confiscates an item (other than alcohol) at embarkation they hold it and you can collect it at debarkation post-cruise. Just don’t forget to stop for it.
I thought I would come back here to share my experience.
There were no issues at all I'm bringing the lightsaber on the cruise and it was also not an issue in bringing it as hand luggage on and international and domestic flight to Australia. Everyone seemed pretty across it even in Australia
"There are options here, Gavin. First, you are permitted to bring your lightsaber onboard your Disney Cruise ship. If you check the list of prohibited items, you'll see an exception is made for store-bought light sabers, which your Savi's Workshop lightsaber is. It's under the Toy Exceptions list, so you're good to go there. I myself saw several Savi's lightsabers on a Star Wars Day at Sea cruise. "
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