When leaving the ship, always take your passport, a credit card and the phone number of the port agent in case you need assistance on land. / Ingolf Pompe/Getty Images
Schedule: Arrive at your departure destination a day early; cruises will not wait for flight delays and lost luggage.
Upgrade: On the final payment date, many reserved rooms are released. Mark it on your calendar to call for a better cabin. Don’t rely on a waitlist.
ID: Scan your passport, list of meds, driver’s license and credit card phone contacts and e-mail them to yourself for access in an emergency.
Cellphones: Many ships now have cellphone service at sea. Get a temporary international plan for texting, and turn off your data roaming to avoid hefty fees.
Research: Look for a ship’s cleanliness violations and outbreak updates on the Centers for Disease Control and Prevention’s Vessel Sanitation Program site at cdc.gov/nceh/vsp.
Check in: Register your whereabouts with the State Department in case of emergency at travelregistration.state.gov.
Valuables: Many people have access to your cabin. Always put valuables and extra credit cards in the safe.
Bags: Pack swimsuits and a change of clothes in your carry-on, because your bags could take hours to be delivered to your cabin. And pack an outfit in your companion’s suitcase in case your bag is lost.