IMPORTANT DOCUMENTS: Leave your passport in your safe. You only need to  bring your government issued ID and your sail and sign card with you when you leave the ship, as well as your shore excursion tickets (if applicable). Check with your cruise for current recommendations or changes. There are usually  signs as you exit the ship.

Most importantly, put the contact information for the cruise line's port agent in your phone—they're the local contact who can alert the ship if any emergencies or delays arise on shore.