structural:scholar_edition, linguistic:voice_change, information:highlighting
Features

The strait is approximately 570 km (310 nmi; 350 mi) long and 2 km (1.1 nmi; 1.2 mi) wide at its narrowest point (Carlos III Island, west of Cape Froward). The northwestern portion of the strait is connected with other sheltered waterways via the Smyth Channel. This area is similar to the Inside Passage of Alaska. South of Cape Froward, the principal shipping route follows the Magdalena Channel. The climate is generally foggy and cold, and the course is convoluted with several narrow passages. It is several hundred miles shorter than the Drake Passage, but sailing ships, particularly clipper ships, prefer the latter. Its major port is Punta Arenas, a transshipment point for Chilean mutton situated on the Brunswick Peninsula. Exemplifying the difficulty of the passage, it took Magellan 38 days to complete the crossing.

The eastern opening is a wide bay on the border of Chile and Argentina between Punta Dúngeness on the mainland and Cabo del Espíritu Santo ("Cape of the Holy Spirit") on Tierra del Fuego, the border as defined in the Treaty of Peace and Friendship of 1984 between Chile and Argentina. Immediately west are Primera Angostura and Segunda Angostura, narrows formed by two terminal moraines of different ages. The Primera Angostura is the closest approach of Isla Grande de Tierra del Fuego to mainland South America. Farther west lies Magdalena Island, part of Los Pingüinos Natural Monument. The strait's southern boundary in the east follows first the shoreline of the Isla Grande de Tierra del Fuego, then the northern end of the Canal Whiteside and the shoreline of Dawson Island.

The western part of the strait leads northwest from the northern end of the Magdalena Channel to the strait's Pacific entrance. This is flanked on the south by Capitán Aracena Island, Clarence Island, Santa Inés Island, Desolación Island (Cabo Pilar), and other smaller islands, and on the north by Brunswick Peninsula, Riesco Island, Muñoz Gamero Peninsula, Manuel Rodriguez Island, and other minor islands of the Queen Adelaide Archipelago. Two narrow channels connect the strait with Seno Otway and Seno Skyring. A broader channel, Smyth Channel, leads north from the strait between Muñoz Gamero Peninsula and Manuel Rodriguez Island. Francisco Coloane Marine and Coastal Protected Area, a sanctuary for humpback whales, is located in this area. This part of the strait lies on the elongated Magallanes-Fagnano Fault, which marks a plate boundary between the South American Plate and the Scotia Plate. This fault continues southward under Almirantazgo Fjord and then below Fagnano Lake. Possibly, new tourism industries could be established in the eastern part of the strait for watching southern right whales, as the number of observations in the area has increased in recent years.

In the more well-defined northeastern course of the strait various bays stand out in its geography. Pecket Bay (Spanish: bahía Pecket) is a shallow and somewhat closed bay in the strait located near where Brunswick Peninsula is as narrowest. San Gregorio Bay (Spanish: bahía San Gregorio) is an open bay located in the north coast of the strait. Opposite Pecket Bay is Gente Grande Bay (Spanish: bahía Gente Grande) in Tierra del Fuego.