There's no single Antarctica-wide six month rule, but you have to satisfy several standards at once. South Georgia requires validity through your permit period plus 4 weeks. Falkland Customs and Immigration recommends at least 6 months remaining at entry. Your gateway countries, your airline and your operator each apply their own. The safe answer is to renew anything with under 6 months left unless every relevant authority confirms otherwise.
A passport that's valid on your return date is not automatically enough. That assumption is the most common document mistake we see.
Names matter as much as dates. Your passport name should match your airline ticket, cruise booking, South Georgia permit and insurance documents exactly, including middle names where required. A mismatch can stop an online medical form linking to your booking or cause a denied boarding. Send any legal name change to us and the operator well before final documents are issued.
If you hold two passports, ask each relevant immigration authority which one to use for entry, exit, visa applications and the cruise manifest, then keep it consistent across everything. Don't switch mid-trip.
If a passport is lost or stolen, report it to the issuing authority first, then tell the airline, us, the operator, your insurer and anyone who issued a visa or permit. A replacement usually carries a new number, so permits and manifests may need reissuing.