Yes, you can use the Carnival HUB App on your cruise without purchasing an internet or Wi-Fi package. Upon boarding the ship, you simply connect your phone to the ship's guest Wi-Fi network (often named "Carnival Guest") and put your phone in Airplane Mode. The app is designed to communicate with the ship's internal servers for free, allowing you to view daily schedules (the "What's Happening" guide), check your onboard "Sail & Sign" account balance, view restaurant menus, and see digital ship maps. There is one notable exception: the "Chat" feature, which allows you to message other guests on the ship, typically requires a one-time activation fee of $5 USD for the duration of the cruise. While the app is free to use for shipboard information, you will not be able to browse the internet, check external emails, or use social media apps unless you buy one of Carnival's tiered Wi-Fi plans (Social, Value, or Premium).