PUNTA ARENAS, Chile -- We are on a bus that is carrying us to a port where we will load up a ship. Nothing unusual about that.
Nothing except for our fat wool hats, puffy penguin parkas, and knee-high insulated boots. Nothing but where we are (at the southernmost tip of Chile) and where we are going (to the isolated, ice-walled bottom of the world).
We know cruises are supposed to be warm. But do we care? We thumb our face-masked noses at the idea of palm trees. We are explorers booked on Lindblad's steel-prowed, spray-glazed Endeavor.
Stadium-sized icebergs, the Falklands, South Georgia Island, and the continent of Antarctica itself are our goals.
Antarctica. No one lives there except a handful of scientists. It is the world's driest desert and its ultimate cold spot, thanks to winds as sharp as 199 miles per hour and temperatures reaching as low as minus 128.
Lindblad Expeditions was the first outfitter and cruise line to bring tourists here on a regular basis -- they've done it since 1966. And the 110-passenger Endeavor is engineered for ice. There's a 40-foot-high crow's nest at the bow to keep an eye out for dangerous floating chunks. And chairs in the dining room are wave-proof: They are chained to the floor.
As we sail through the Strait of Magellan and begin to dip and roll, one early surprise is the other passengers. Some seem almost famous. Bill Cole, a performer from Pasadena, Calif., tells me his was the voice of the original theme song for the television show "Gilligan's Island." When I ask if he ever met the Skipper, Ginger, or Mary Ann, however, he says no, so I'm slightly skeptical.
For other passengers, extreme adventures are like day trips to a local beach.
Audrey and Gerry Olson from Tonto Verde, Ariz., are first-timers on this trip, but they've already bagged the North Pole.
"We went on a Russian icebreaker," says Gerry, "though not all of the ships make it. They had a barbecue for us right on the Pole. Grilled sausages, I think it was, and champagne."
Arrival at the Falkland Islands, which seem as green and treeless as Scotland, brings warnings. Who knew the islands were still sprinkled with land mines left over from the 1982 turf war between Britain and Argentina?
Along with others, I have a very long look at the Minefield Clearance Situation Map posted on the Veranda Deck. I step gingerly when, in the intrepid Lindblad way, we are ferried ashore in a fleet of Zodiac boats. Later, we climb a hill to view the wreckage of an Argentinean helicopter peppered with bullet holes, shot down early in the conflict.
Next stop: South Georgia Island, which though free of land mines, is a powder keg of breeding, molting, and arguing animals and birds.
"Remember," we are told in a printed notice, "do not approach penguins, albatrosses, seals, or any other wildlife so close that they move away from you, act agitated, or change their behavior."
No worries here. It's the wildlife that approaches us. For starters, landing on a beach in South Georgia means running a gantlet of 600-pound fur seals -- and elephant seals that top out at twice the tonnage of a typical SUV.
Although both species smell like fish sticks and produce resonant belches, it is the fur seals that are the problem. They show us mouthfuls of wolf-sharp choppers. And, we are told, they bite. Since we've interrupted their spring-break beach party, they are annoyed. Luckily, our guides from the ship know expert tricks with tripods and clapping hands to keep them at bay.
As for elephant seals, no sweat. Think vacuum-cleaner bags with snouts, used ones that are full to the brim. We step around them to the marquee attraction: hundreds of thousands of walking, whistling, swimming, nipping King penguins.
Earlier in the trip, we had sighted a few of these fat guys floating past on top of ice chunks. But this is penguin central. It is not a colony. It is a noisy city.
Penguins surround us. Penguins eye us. And penguins pass by like pedestrians on Newbury Street.
Some stop short for pictures, some have urgent business, and here and there are penguin chicks that instead of the grown-up black and orange and white are bundled up in fluffy down.
Susan Hickey of Juneau, Alaska, tells me she feels inspired by this color-coordinated penguin population.
"I'm thinking of remodeling my kitchen," she says, "and I like the idea of all these contrasting shades."
The weather has been eerily warm so far, but temperatures sink into the 20s and it begins to sleet as we circle the South Georgia grave of famous polar explorer Sir Ernest Shackleton. We drink a toast to him with paper cups of Irish whiskey.
It is time for our own Shackleton adventure. The plan is this: Those who are up for a steep 1,000-foot climb and hike over loose rocks and snow will try to retrace the last segment of the explorer's route back to civilization after his catastrophic shipwreck in 1915.
With the ship's doctor along just in case, a band of us stagger into the hills over South Georgia's Fortuna Bay. Most have protective polypropylene or GORE-TEX gear on top and below. I rely on a couple of cotton shirts, a pair of flannel-lined khakis, and my L. L. Bean duck boots that have a tendency to take on freezing seawater whenever we go ashore.
This equipment works fine until we get to a glacier that drops down toward our destination, an abandoned whaling station where the ship has sailed around to meet us. The way to deal with the glacier, we decide, is to sit down on the snow, lean back, and slide.
We become falling objects clutching day-packs, tripods, and cameras. Look out below!
We are rocketing downward and I am shouting with joy until my khakis begin scooping up slush and I start spinning sideways while I slide. I am feeling wet instead of icy. Why? I have fallen through the snow and into a moss-slick, numbingly cold mountain stream.
Once everyone stops laughing, I am fished out and force-marched to the ship to dry off. The Lindblad line takes pains to make sure its passengers stay sensibly warm and safe. I get a well-deserved lecture on using the cold-weather gear I have been issued and have packed for the trip.
Back at sea again, we're on our final leg to Antarctica and we are busy toasting some more. This time, it isn't Shackleton we drink to, but our hike, and there are shots of aquavit, plates of pickled herring, and glasses of beer. Then the storm hits.
Wind, waves, nausea, aftertastes of herring, bitter regrets about the aquavit and beer. I try to chill out in the library but things seemed permanently tilted. The horizon sticks up threateningly like a spear and I head out on deck to find an eerie light in the sky that's leaking from somewhere and swirling spray whipped up by Godzilla winds.
Finally, late in the evening, things get quiet. Everyone is out by the rail watching the sea calm down, and they are snapping pictures of pure, prismatic orange and purple light that has spread over the ship like a wild umbrella.
It is the middle of December. According to the ship's program, the sun will set at exactly 11:57 p.m., and after a few hours of afterglow, will pop up again at 3:22 a.m. No one even tries to sleep.
Air temperature: 26 degrees. Water temperature: 29 degrees. Latitude: between 65 degrees south and 64 degrees south. Ship's position: just southeast of James Ross Island off the Antarctic Peninsula.
We have made it.
The White Continent is ours to claim. Our official welcome is the sound of crunching. The sea is solidly frozen, and though the ship reverses its engines, punches, and pushes, we can go no farther.
Later, we will load the Zodiacs and make landfall on the continent at a slippery, wind-scoured beach called Brown Bluff (part of the Tabarin Peninsula). We will visit snowy Antarctic islands, and a few of us will even slip underwater for a wink-quick, breath-swiping "swim."
Somehow, however, it is this second when we are shoving up against sea ice that makes the abstract idea of the Pole entirely real.
The world is definitely round. Now I know this. Cold and oval as a snowball, one that spins so crazily that the sun stays up most of the night and the ocean reaches its end.
If I can get my hands around it, this I promise:
I will come back again.
Peter Mandel is an author of children's books, including two about ships: "Boats on the River" (Scholastic) and "My Ocean Liner" (Stemmer House). He lives in Providence. 
