By dawn the ship is sailing up Admiralty Sound (Seno Almirantazgo), a spectacular offshoot of the Strait of Magellan that stretches nearly halfway across Tierra del Fuego. The snowcapped peaks of Karukinka Natural Park stretch along the north side of the sound, while the south shore is defined by the
deep fjords and broad bays of Alberto de Agostini National Park. We go ashore at Ainsworth Bay, which harbors copious bird life and a colony of southern elephant seals which can sometimes be spotted from the Zodiacs. Two guided excursions are available: one is along the edge of a stream, peat bog and beaver habitat to a waterfall-and-moss-covered rock face tucked deep inside a pristine subpolar forest; the other is a more strenuous hike along the crest of a glacial moraine. Both afford views of Marinelli Glacier and the Darwin Mountains.
Leaving Ainsworth Bay behind, we sail west along the sound to the Tucker Islets. After lunch, we board the Zodiacs again for a closeup view of the Magellan penguins that inhabit the tiny islands. More than 4,000 penguins use Tucker as a place to nest, give birth and nurture their chicks. Many other bird species also frequent the area including king cormorants, oystercatchers, Chilean skuas, kelp geese, dolphin gulls, eagles and even the occasional Andean condor.