Australia–Singapore Submarine Cables: The Complete Guide

Australia–Singapore Submarine Cables: The Complete Guide

Based on GeoCables submarine cable database and TeleGeography data, March 2026 Four submarine cable systems directly connect Australia to Singapore, carrying the bulk of internet traffic between one of the world's largest countries and Southeast Asia's most important internet hub. These cables span approximately 4,600km of the Indian Ocean and the waters around the Indonesian archipelago — a route that has seen massive investment over the past decade as Australia's digital economy has grown.

The Four Direct Cables

1. Australia-Singapore Cable (ASC) — 4,600km

The Australia-Singapore Cable (ASC) connects Perth, Western Australia to Tanah Merah, Singapore via Christmas Island and Jakarta, Indonesia. At 4,600km, it is one of the most direct routes between the two countries, following the eastern Indian Ocean rather than going around the Indonesian archipelago. ASC is part of the broader Indigo cable system — a consortium project that includes both INDIGO-West and ASC as complementary segments forming a complete Australia–Asia backbone. Landing points: - Perth, WA, Australia - Tanah Merah, Singapore Route: Perth → Christmas Island → Jakarta, Indonesia → Singapore

2. INDIGO-West — 4,600km

INDIGO-West is the other half of the Indigo cable system, also connecting Perth to Singapore at 4,600km. Where ASC follows one path through the Indonesian waters, INDIGO-West connects to Tuas on Singapore's western coast — giving the Indigo system two separate Singapore landing points for redundancy. Consortium owners include: AARNet (Australia's academic network), Google, Indosat (Indonesia), Singtel (Singapore), and Telstra (Australia). The Indigo system was a landmark project when it launched — the first time Google invested directly in a cable serving Australia, and the first major cable built specifically to address Australia's chronic bandwidth shortage to Asia. Landing points: - Perth, WA, Australia - Tuas, Singapore

3. Asia Connect Cable-1 (ACC-1)

ACC-1 connects Darwin, Northern Australia to Singapore — a different geographic approach than the Perth-based Indigo cables. Darwin is approximately 3,200km from Singapore, making this one of the shortest possible Australia–Singapore routes. The Darwin landing makes ACC-1 particularly valuable for northern Australia's connectivity, and for providing a diverse route that doesn't pass through the congested waters around Java. Landing points: - Darwin, NT, Australia - Singapore

4. Hawaiki Nui 1

The newest addition to the Australia–Singapore corridor, Hawaiki Nui 1 takes a dramatically different approach — connecting multiple Australian cities (Brisbane, Sydney, Darwin) to Singapore via Changi. This multi-city design means that traffic from Australia's east coast (where most of the population lives) can reach Singapore without first routing through Perth or Darwin. Landing points: - Brisbane, QLD, Australia - Sydney, NSW, Australia - Darwin, NT, Australia - Changi, Singapore The Sydney and Brisbane landings are significant: they serve Australia's two largest cities directly, rather than requiring east coast traffic to cross the continent to Perth first.

Why Singapore?

Singapore is not just a convenient waypoint — it is the internet capital of Southeast Asia and one of the most important internet exchange points in the world. The SGIX (Singapore Internet Exchange) and multiple carrier-neutral data centers in Singapore connect onward to: - Southeast Asia: Indonesia, Malaysia, Thailand, Vietnam, Philippines - South Asia: India, Sri Lanka, Bangladesh via SEA-ME-WE cables - East Asia: China, Japan, South Korea via multiple Pacific cables - Europe: via SEA-ME-WE 3, 4, 5, 6 and AAE-1 cables through the Middle East - North America: via transpacific cables through Guam and Hawaii For Australia, Singapore is the gateway to the world. A packet from Sydney heading to London will almost certainly pass through Singapore before continuing west.

Latency: What to Expect

The theoretical minimum latency for the 4,600km Perth–Singapore route is approximately 23ms (at 200,000 km/s in fiber). Real-world round-trip times are higher due to routing overhead: - Perth → Singapore: ~45–55ms RTT (excellent) - Sydney → Singapore: ~80–90ms RTT (good — adds east coast → Perth terrestrial segment) - Melbourne → Singapore: ~85–95ms RTT (good) These numbers make Australia–Singapore one of the better-connected country pairs in the Asia-Pacific region, especially compared to Australia's connections to Europe (280–320ms) or South America (300ms+).

The Bandwidth Revolution

Before the Indigo cables arrived in 2019, Australia's connections to Singapore relied primarily on older systems with limited capacity. The result was expensive international bandwidth that constrained Australia's cloud computing adoption and made Australian latency to Asian servers noticeably worse than comparable distances elsewhere. The Indigo system — with its Google and Telstra backing — brought a step-change in available capacity. Combined with ACC-1 and Hawaiki Nui 1, Australia now has genuine redundancy on the Singapore route: if any single cable is cut or suffers a fault, traffic can reroute across the remaining systems with minimal impact.

Christmas Island: The Unusual Waypoint

The ASC cable passes through Christmas Island — an Australian territory in the Indian Ocean, 1,550km northwest of Perth and 360km south of Java. The island has a population of around 1,800 people, and the cable landing there gives Christmas Island its primary international internet connection. This is a common pattern with submarine cables: remote territories and small islands often get connectivity as a "bonus" landing point on cables that are passing nearby anyway.

Monitoring on GeoCables

GeoCables tracks submarine cable health and latency across the Australia–Singapore corridor. You can view real-time status of individual cable segments and historical RTT measurements from our RIPE Atlas probe network.

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View individual cable pages: ASC → · INDIGO-West → · Hawaiki Nui 1 → Calculate Australia–Singapore route →