Antarctic cruises from Ushuaia

From November to March, the expedition ships tied up along Ushuaia's waterfront are waiting for their turn to head south. It makes sense: the city is one of the five internationally recognized gateways to Antarctica, and it lies about 1,100 kilometres from the Antarctic Peninsula, the part of the frozen continent closest to South America.

The voyage starts down the Beagle Channel and soon opens onto the Drake Passage, the stretch of sea more than 800 kilometres wide between Cape Horn and the South Shetland Islands. It is known as one of the stormiest seas on Earth, and waves over ten metres high are not unusual. Expect around two days at sea each way: time for onboard talks, for watching the ocean from the deck, and for getting your sea legs.

On the other side, everything changes. Ships thread between icebergs through sheltered channels, with ice-covered mountains dropping straight into the water. One of the most sought-after is the Lemaire Channel: 11 kilometres long and only 600 metres wide at its narrowest. Early in the season, ice sometimes blocks it and ships have to go round the outside of Booth Island instead.

Expeditions last anywhere from 10 days to three weeks, depending on the route. Landings on the peninsula are made by inflatable boat, with no more than a hundred people ashore at a time, and ships carrying over 500 passengers cannot land anyone at all. That is why most departures from Ushuaia use small vessels, built for stepping onto the snow rather than just looking at it from the deck.

• Tour type: Ship-based expedition, scenic and wildlife watching
• Difficulty level: Low to moderate (the Drake crossing can be rough)
• Tip: Pack seasickness medication for the Drake Passage and waterproof layers; if going ashore matters to you, check how many passengers the ship carries before booking.