Bringing an e-cigarette (vape) on a cruise requires strict adherence to both security and smoking policies. All major cruise lines like Carnival, Royal Caribbean, and Norwegian require you to pack your e-cigarette and any spare lithium batteries in your carry-on luggage rather than checked bags, as lithium batteries are a fire hazard in the cargo hold. While you are allowed to bring the device on board, you are strictly prohibited from using it in your stateroom or on your private balcony; doing so can result in a "cleaning fee" of $250 or more and potential removal from the ship. Vaping is only permitted in designated smoking areas, which are usually located on specific outdoor decks or within the casino. Additionally, you should ensure your e-liquid is in a leak-proof container; while there is no universal limit on the amount of juice, it must comply with standard "prohibited substance" rules, meaning CBD or THC-based liquids are strictly forbidden regardless of their legal status in your home port.