THE ANTARCTIC PENINSULA -- This is the first in a series of articles on dream vacations, what some might call bucket-list or once-in-a-lifetime trips.

Exactly 22 hours after leaving Ushuaia, Argentina, which calls itself “the end of the world,” the expedition ship Fram reached the Southern Ocean, which circles Antarctica — the real end of the world.

The captain’s P.A. announcement interrupted the lecture on that frozen continent’s ecology, but the passengers cheered. For me, and for every passenger I was to ask, reaching Antarctica had been an impossible dream. Until we realized we could do it, almost as simple as booking a cruise.

Almost.

When we reached the Southern Ocean — the water temperature dropped an astonishing 7 degrees when we entered that continental current — the Norwegian ship Fram was little more than halfway to our first trip ashore. That meant we might be facing another night and day like the first one — grabbing for corridor handrails or the backs of chairs to brace against the exaggerated rolling of the ship in what can be the planet’s most hostile 600 miles of sea.

But our progress also meant we were that much closer to a continent so massive that if you put the United States on top of Antarctica, there would be more than 1 1/2 million square miles uncovered. Meanwhile, the United States would be sitting on ice more than a mile and a half thick.

We’d be landing in early summer, when the temperature would climb to freezing only one of our four days there.

We could barely wait.

Our patience was tested the next morning while still approaching: The ship motored into a mini-blizzard whose tiny snowflakes turned to sleet so thick the Fram seemed fogbound. The deck became slippery with snow.

But once the ship passed the storm and reached the islands off the Peninsula, the 122 passengers understood what Dorothy felt as she opened the farmhouse door:

We found ourselves under a brilliant blue sky in a majestic land, its horizons defined by mountains and perennial winter.

All around us were huge granite peaks whose jagged outlines were softened by thick coats of snowdrift. Icebergs glistened pearly white or an eerie neon turquoise, or both. Irregular clangs and chungs sounded throughout the 373-foot-long ship as its hull plowed through drift ice, remnants of building-sized icebergs still within view.

We could see penguins leaping above the surface of the clear sea for fractions of a second before darting ahead, underwater.

The eight-day voyage had become an expedition. And on expeditions there are often surprises.

BEING FLEXIBLE

“All stated times and activities are changeable due to weather conditions, or other circumstances out of our control,” the daily agenda reminded passengers.

That’s why the captain slowed the Fram in order to trail three fin whales on Day Three. And that’s why the much-awaited scenic cruise in the eight-passenger landing boats was cancelled both on the night of Day Five and the following morning. As we swarmed the three observation decks to stare at a monster slab of ice a mile or so in front of the bow, the captain explained over the P.A.:

“Well, this is what happens when a 500-meter-wide iceberg enters a 550-meter-wide channel. We cannot send in the little boats because they must always be near the big ship.