Short of Antarctica itself, some of the Southern Hemisphere’s most awesome scenery occurs in the Beagle Channel and southern Tierra del Fuego .
Fairly few visitors see Tierra del Fuego’s splendid fjords, barely changed since Darwin’s 1833 sojourn. Other than your own yacht or someone else’s, the only way to do so is a cruise from Punta Arenas  to the Argentine port of Ushuaia  and back on Mare Australis or Via Australis.
Routes vary according to weather conditions in this notoriously capricious climate. After an evening departure from Punta Arenas’s Muelle Prat, the vessel crosses the Strait of Magellan to the Seno del Almirantazgo (Admiralty Sound), a westward maritime extension of the Lago Fagnano  trough. Passengers usually go ashore at Bahía Ainsworth, near the Glaciar Marinelli.
After a night’s sailing, the ship may enter the Fiordo D’Agostini, a glacial inlet named for the 20th-century Italian priest and mountaineer who explored the Cordillera Darwin. When winds make it impossible to approach Glaciar Serrano, the ship anchors at the more sheltered Glaciar D’Agostini.
After navigating Canal Cockburn, where ocean swells can rock the boat, the vessel turns into the calmer Canal Ocasión and enters the Beagle Channel’s north arm, sailing past the so-called Avenida de los Glaciares, a series of glaciers named for European countries. Traditionally, after the night’s sailing, the ship steamed to Isla Navarino’s Puerto Williams  for passport control and excursions before continuing to Argentina, but formalities now take place at Puerto Navarino.
Proceeding to Ushuaia , all passengers spend the night aboard; those returning to Punta Arenas have the day free before returning to the ship, while new passengers check their bags downtown before boarding in late afternoon.
After reentering Chile at Puerto Navarino, the ship proceeds south to Cabo de Hornos (Cape Horn), and, wind permitting (less than 45 knots), passengers disembark to visit the small Chilean naval detachment and hike to the stylized albatross sculpture that symbolizes sailors who lost their lives “rounding the Horn.”
If conditions permit, the captain can choose to round the Horn himself before proceeding north to Bahía Wulaia, on Navarino’s western shore. Here passengers visit the site of an early mission where, in a notorious incident, the Yámana massacred all but one of the Anglicans and their crew. Passengers can take a short but steep hike with panoramic views of the bay or an easier shoreline walk with birdlife, including Magellanic oystercatchers.
On departure, the ship turns westward through the Beagle Channel’s north arm, again passing the Avenida de los Glaciares and entering Fiordo Pía (Pía Fjord), where dozens of waterfalls cascade down sheer metamorphic slopes from the Glaciar Pía and passengers take a short hike. Proceeding through the afternoon and the night, the boat starts the last full day navigating the Fiordo Chico (Little Fjord), where passengers board Zodiacs to approach Glaciar Plüschow, named for a German pioneer aviator who took the first aerial photos of the Cordillera Darwin.
In the afternoon, the Glaciar Águila is the site of an easy shoreline walk or a demanding slog through knee-deep mud in a southern beech forest (the video footage of this hike, shown the night before in an orientation session, is priceless). On the final morning, the boat sails to Isla Magdalena (see Monumento Natural Los Pingüinos ) before returning to Punta Arenas .
For more information on what to expect while you're onboard, click here .