The Sunda Strait

Between Java and Sumatra lies a strait best known for the volcano in its middle. The Sunda Strait links the Java Sea with the Indian Ocean, and for two centuries it was the gateway Dutch East India Company ships used to reach Batavia, today's Jakarta. In 1883 Krakatoa, which rises from the strait, erupted and sent tsunamis across its shores that killed about 36,000 people. Today the strait matters less as a global shipping lane than as a busy domestic chokepoint: ferries shuttle around the clock between Merak on Java and Bakauheni on Sumatra, carrying trucks, buses and millions of passengers a year between Indonesia's two most populous islands, while some international ships use it as an alternative to the Strait of Malacca.

The strait runs roughly southwest to northeast between the southern tip of Sumatra and the western end of Java. It is only about 24 kilometers wide at its northeastern end, between Cape Tua on Sumatra and the Java coast near Merak, and widens to more than 100 kilometers where it opens onto the Indian Ocean. The southwestern part is broad and deep, but the northeast is shallow, with depths of about 20 meters in places, along with strong tidal currents, sandbanks and offshore oil platforms that make it difficult for large ships. Islands including Sangiang, Sebesi and the Krakatau group lie in the strait, and Anak Krakatau, the young cone that rose from the sea in 1927, still erupts. Ujung Kulon National Park, a UNESCO World Heritage Site and the last refuge of the Javan rhinoceros, lines the Java shore.

Because the strait offered a shorter route from the Cape of Good Hope to Batavia than the Strait of Malacca, Dutch ships favored it from the 1600s, and it served as a main entry to the East Indies spice trade. The 1883 eruption reshaped the seabed and coast, and in December 2018 a flank collapse of Anak Krakatau triggered a tsunami that killed more than 400 people on the shores of Java and Sumatra. A bridge between Java and Sumatra has been proposed several times, most recently through a 2012 agreement for an $11 billion road and rail link, but the plan was shelved in 2014. Since July 2020 an IMO traffic separation scheme has guided ships through the strait, which forms part of Indonesia's first archipelagic sea lane.

• The Strait of Malacca
  The long channel between Sumatra and the Malay Peninsula, the world's busiest oil chokepoint alternative to
• Java
  The world's most populous island, the crowded core of Indonesia borders
• Sumatra
  A vast volcanic island anchoring western Indonesia borders
• Indian Ocean
  The world's third-largest and warmest ocean connects to
• Indonesia
  The world's largest archipelago, spanning two oceans located in
• The Lombok Strait
  The deep Indonesian channel between Bali and Lombok that takes supertankers too deep-laden for the Strait of Malacca neighboring Indonesian strait
• Krakatoa
  The Indonesian volcano whose 1883 eruption was heard across the world volcano in