It's a small window—though the experience is anything but. For four months out of the year—from November through February, when the climate is manageable (between 30 and 50 degrees), Antarctica is not just for the birds (penguins to be exact). 
For the thrill seekers and the curious, visiting the White Continent, as it's fittingly called, is a once-in-a-lifetime opportunity, which many have called an "ethereal experience." And, why not? Besides the majesty of idling icebergs, lakes covered in blue ice and snow cornices, the region is home to such curious creatures as Adelie penguins and elephant seals. (Note: Antarctica literally means "no bears," so if you are expecting to see polar bears, you're in the wrong hemisphere. Book an Arctic expedition.)
While Antarctica is full of beauty and awe, one thing it has is a dearth of lodging options. Hilton Hotels has yet to plant a flag here. Nor has Marriott made it there. Even the Four Seasons can't withstand Antarctica's climate. Luckily, those who dare to brave the elements have a foolproof method for enduring the odyssey: cruising. 
Cruising Antarctica is not for the weak at heart, and it's also best suited for more seasoned cruisers. If you haven't cruised before, you might want to first get your feet wet in the Caribbean, or, if you are not a beach person, an Alaska cruise would be more suitable. Alaska, while not nearly the same as Antarctica, can act as a primer before graduating to an Antarctic cruise.
Likewise, be prepared to shell out some coin for the expedition, as a trip of this nature should be called. Most itineraries are longer (not your three-or four-day, garden-variety cruise) and can last upwards of 20 days. In sum, the region is for the well-traveled, high-income bracket visitor who's searching for experiences that are out of the ordinary. You should have a sort of "boldly going where no man has gone before" notion, to steal a line from Star Trek. 
That Antarctica is an emerging destination for cruisers is a testament to the growing popularity of not only cruising but also baby boomer travel and the growth of groups looking to collect personal experiences as opposed to material gains. Antarctica fits ideally into this frame of mind, as it offers an experience that only a relative few have enjoyed.
Moreover, this trend offers tremendous opportunity and an upside for cruise lines, which are always on the lookout for new entry markets. Cruising has grown up over the past 20-odd years to be more than just a Caribbean or warm-weather conveyance or getaway; seasoned travelers, in particular, want more out of their vacations than just fun and sun. Antarctica fits this bill to a T, and with relatively few options in the region, the cruise lines, out of necessity, possess a virtual monopoly on vacations here.
Cruise lines have noticed the growing demand and are even making cash plays to acquire ships that are designed specifically to transit the region. Last September, luxury cruise line Silversea Cruises acquired Society Expeditions' World Discoverer, since renamed HSH Prince Albert II, explicitly for polar expeditions. Silversea joins luxury cruise colleague Regent, which too has its own expedition ship.
While the continent is said to have been discovered in 1820 by Russian explorers, it's still being settled by the cruise lines, who are quick to recognize the environmental responsibility that comes with plying such an unspoiled and geologically rich area. And even though Antarctica is becoming a more popular destination, only some cruise ships can make it through the region. Some 98 percent of Antarctica is covered by ice, meaning larger ships would have a tough time navigating the ubiquitous jagged ice floes that are indigenous to the region. That leaves the task to smaller ships, which have far better maneuvering capabilities and specially designed hulls that can withstand the constant barrage of ice.
Just remember, Antarctica is not a choice destination if you are expecting shopping, fine dining and things to do inside—though you probably already knew that. The region is desolate, wherein lies its pull, and a place that in today's hustle and bustle, may possibly be one of the last peaceful havens on Earth.