And then there are simply the bragging rights: the thrill of being among an elite group of travellers who have ventured this close to the bottom of the world – an achievement that you and your companions will no doubt celebrate with a glass of fizz as you cross the fabled line, and with not another ship in sight.

A typical Circle Cruise will journey down the western side of the Antarctic Peninsula and cross the Antarctic Circle via Crystal Sound – a spectacular stretch of sea named for the research on ice crystals conducted there. Just north of the Circle there are several possible stop-offs, including the Fish Islands, where a zodiac cruise among the ice will bring you close to large colonies of adelie penguins and blue-eyed shags. 

Once across the Circle, your stops may include Detaille Island, at 66°52’, where you can visit a British Antarctic Survey research base hurriedly abandoned in 1958, with sleeping bags still strewn across beds and bottles of HP sauce on the shelves. It’s a stark reminder of the precarious nature of life in the Antarctic. Conditions permitting, you may also explore Lallemand Fjord, where emperor penguins are occasionally seen.

Some voyages head even further south, passing east of Adelaide Island via an ice-clogged channel called ’The Gullet’ and onwards into the vast expanse of Marguerite Bay. Here, you are likely to encounter whales, including humpbacks and minkes, which gather to hoover up the vast quantities of krill found here in late summer. Hikes on Jenny Island allow fabulous views of the surrounding panorama.

The distance you travel south will depend upon the state of the ice and the length of your voyage. Some cruises may reach the vast ice shelves at Wilkins Sound or George VI Sound to the south of Marguerite Bay. Conditions will determine what’s possible, so be prepared to throw the itinerary overboard. Equally, cruises may flip the itinerary, capitalising on a good weather window to start by sailing due south to the Antarctic Circle then working their way north back up the Peninsula. This is what happened on my own trip, when I awoke on my first morning, after crossing the Drake Passage, to find myself already south of the Circle.

Far to the east of the Peninsula, and further south still, lies the Ross Sea. This offers another approach to crossing the Antarctic Circle, but on a much longer cruise that departs from New Zealand. A Ross Sea cruise is a serious adventure – a chance to sail to the edge of the vast Ross Ice Shelf at 77° south, with its great calving glaciers, and to visit Ross Island, with the historic huts of Scott and Shackleton and the smoking 3,795m-summit of Mount Erebus. Ships with helicopters even offer an opportunity to overfly McMurdo Dry Valleys in Victoria Land – the driest place on earth, where no rain has fallen for over 2 million years.

The Ross Sea’s biggest wildlife drawcard is emperor penguins. Although the inland colonies of these Antarctic icons are too remote to access, you are likely to encounter smaller groups out on the ice. You should also see Antarctica’s largest colonies of Adelie penguins, and a healthy population of orcas, sometimes seen sweeping seals off ice floes using their unique wave-wash method. En route from New Zealand, cruises will drop by at several of the sub-Antarctic Islands, including Macquarie, Enderby, Snares and Campbell Island, each home to unique fauna and flora – including several endemic penguins.

Seabirds

Various members of the petrel family occur around the Antarctic Circle. These include the big southern giant petrel, the gull-like southern fulmar, the diminutive Wilson’s petrel – often seen fluttering around surfacing whales – and the pure-white snow petrel, which perches on icebergs and has been recorded at the South Pole. Albatrosses, closely related to petrels, tend to be seen further out at sea and especially on the Drake crossing. They include the black-browed, grey-headed, light-mantled sooty and – biggest of all – the wandering albatross, with its 3.2m wingspan. Other seabirds you should encounter include the Antarctic or blue-eyed shag, which often breeds alongside penguins, the ubiquitous kelp gull and the elegant Antarctic tern. Two birds often seen scavenging around penguin rookeries are the snowy sheathbill and the Antarctic skua. The latter is a powerful and aggressive member of the gull family that will accompany your ship as far south as you go.

A host of other seabirds and several rare endemic land birds occur on the sub-Antarctic Islands visited by those on a Ross Sea Cruise. On Macquarie Island (Auatralia), these include king, royal and rockhopper penguins.

Whales and dolphins

February is the peak month for cetacean sightings. The humpback whale is the most conspicuous – and most showy – of the large filter-feeding baleen whales that arrive in Antarctica’s fertile waters over summer to feed on krill and other marine life. Along with the smaller, quieter and more solitary Antarctic minke whale, it is often seen near the shore and may approach close to Zodiacs and kayaks. Fin whales are generally seen further out to sea and in the Drake Passage, where other great whales more seldom seen include the blue and the sei. Pods of orca also frequent the Peninsula and Circle regions and may be seen targeting seals on ice floes. I witnessed the hour-long drama of orcas pursuing a fin whale and her calf through the Bransfield Strait, between the Peninsula and the South Shetland Islands – a drama whose end we never discovered. Cruising to the Ross Sea from New Zealand brings a greater chance of seeing sperm whales and southern right whales, while dusky dolphin and Peale’s dolphin may be encountered in the Beagle Channel in and out of Ushuaia.

Seals and sealions

Antarctica is home to four seal species that live around the pack ice. The crabeater seal is the most numerous – indeed it is the most numerous large mammal in the world, with a population in the tens of millions – and is a common sight, generally hauled out in loose groups on the ice. Another sociable species is the smaller and more rotund Weddell seal, a deep-diving specialist that occurs further south than any other seal. The predatory leopard seal is a solitary operator, identified by its spotted coat. It hangs around penguin colonies, where it targets youngsters, and may show great curiosity around Zodiacs. Ross’s seal is the smallest, rarest and most solitary species, and seldom seen. Further north on the Peninsula, you should encounter the enormous southern elephant seal – at up to 5m, the bulls are the largest seals in the world – and the noisy Antarctic fur seal. There are colonies of both species on the South Shetland Islands, and either may turn up at sea anywhere on your voyage.

Footwear

• Walking boots (or sturdy walking shoes): most cruise operators will provide muck boots, but proper walking footwear may be better for any longer hikes
• Trainers/casual shoes to wear on board

Other gear

• Camera and waterproof bag (to protect from splashing during Zodiac trips and landings)
• Binoculars: indispensable if you’re serious about wildlife, especially when scanning at sea
• Sunscreen and sunglasses (polarising glasses are best; the glare off the snow can be blinding) 
• Moisturiser and lip balm: the Antarctic air can be pretty dry