We never take our passports with us when in the Caribbean. However, we do have color copies of the identity part of our passports which we bring, along with driver's licenses and of course the cruise cards. You will need the cruise card and a government issued photo ID to return to the ship. This is what the driver's license is for. The copy of the passport is for if something happens and we either miss the ship, or get into some sort of trouble. We leave the original passports in the safe.