At minimum: passport, every gateway and transit visa or electronic authorisation, cruise confirmation, flight details, proof of insurance, the operator's medical approval, emergency contacts, and a South Georgia Entry Permit if your itinerary calls there. Depending on your circumstances, add minor consent documents, prescription letters, accessibility arrangements, equipment approvals and vaccination certificates. Your operator's final document checklist is the controlling list.
Carry paper and secure offline digital copies of the passport page, visas, permit, cruise confirmation, insurance certificate with its emergency contact numbers, prescriptions and any medical letter. Keep the copies separate from the originals, and leave the itinerary and emergency details with someone at home.
Children need their own valid documents and must meet the operator's age and medical rules. When a minor travels without both parents or legal guardians, transit countries may want a birth certificate, a notarised consent letter, custody documentation or proof of relationship. Requirements differ sharply by country, so confirm them with the consulates and the airline well before travel.