Sunda Strait Live
Every vessel threading the Sunda Strait, on one live map. The narrow passage between the Indonesian islands of Java and Sumatra — connecting the Java Sea, and the wider South China Sea beyond, to the Indian Ocean, and the principal alternative to the Strait of Malacca.
Live vessel positions
Open full-screen ↗Where is the Sunda Strait?
The Sunda Strait lies between the Indonesian islands of Java and Sumatra, connecting the Java Sea — and the wider South China Sea beyond — to the Indian Ocean. Narrow and shallow in places, with strong tidal currents, it carries less deep-draft traffic than the Strait of Malacca, but it is the principal alternative and vital for regional and inter-island traffic. The live map above shows every vessel with an active AIS signal, updated each minute.
Why the Sunda Strait matters
The Sunda Strait separates Java from Sumatra, linking the Java Sea with the Indian Ocean. Because of its depth and navigational hazards it carries less deep-draft traffic than the Strait of Malacca, but it remains the principal alternative to Malacca and a vital passage for regional and inter-island shipping. It is not a canal — it is an international strait. The active volcanic island of Anak Krakatau sits within it, and strong tidal currents run through the channel.
This page exists because that flow deserves a free, public, real-time view — not buried behind a maritime-intelligence subscription. Watch the map. The ships are still moving.
What you're seeing on the map
- Every vessel inside the Sunda Strait bounding box, between the Java Sea and the Indian Ocean, with an active AIS signal.
- Vessel type — tanker, bulk, container, cargo, sailing — colour-coded.
- Direction and speed — heading arrows and speed colours show which way each vessel is transiting.
- Live refresh every 60 seconds on the public feed.
For voyage history, sanction status, ownership chain, and cargo inference, sign in to the Strait Up Maritime app.
Geography
The Sunda Strait is a narrow channel separating Java from Sumatra, running between the Java Sea to the north-east and the Indian Ocean to the south-west. It is about 24 km wide at its narrowest point and shallow in places, with strong tidal currents, and the active volcanic island of Anak Krakatau sits within it. Unlike the Suez or Panama canals it is not an artificial waterway, and unlike the Turkish Straits it is not governed by a dedicated treaty. Its depth and navigational hazards mean it carries less deep-draft traffic than the neighbouring Strait of Malacca.
About the data
Vessel positions come from terrestrial and satellite AIS reception, aggregated across multiple providers and de-duplicated. The public live feed is delayed approximately 60 to 180 seconds from broadcast and covers the public Sunda Strait bounding box only. Commercial users with a paid plan get unredacted access including vessel detail, voyage history, draught classification, sanctions context, and ownership chain.
AIS data is broadcast openly by vessels under the SOLAS V/19 carriage requirement. We aggregate, refresh, and visualise it — we don't operate the broadcasting infrastructure.
Frequently asked questions
Where is the Sunda Strait?
The Sunda Strait lies between the Indonesian islands of Java and Sumatra, connecting the Java Sea — and the wider South China Sea beyond — to the Indian Ocean. Tankers, bulk carriers, cargo ships and inter-island traffic move through it.
How wide is the Sunda Strait?
The Sunda Strait is narrow — about 24 km at its narrowest point — and shallow in places, with strong tidal currents. The active volcanic island of Anak Krakatau sits within it.
Is the Sunda Strait an international waterway?
The Sunda Strait is an international strait, not a canal. Because of its depth and navigational hazards it carries less deep-draft traffic than the Strait of Malacca, but it is the principal alternative and remains vital for regional and inter-island traffic.
How current is the data on this page?
The live map refreshes every 60 seconds from aggregated AIS reception. End-to-end latency from a vessel's actual broadcast to its dot moving on the map is typically 60 to 180 seconds. The hero counter above updates each time you reload the page.
Is this free to use?
Yes. The live map is free and requires no account. If you need vessel detail, voyage history, sanctions context, ownership chain, or draught/cargo inference, those sit behind a paid plan at Strait Up Maritime.
Other chokepoints we cover
The Sunda Strait is one of several maritime chokepoints under continuous observation across Strait Up Maritime. Each has its own live page; the same dataset powers all of them.