Bass Strait-2: submarine cable linking mainland Australia and Tasmania
The Bass Strait-2 submarine cable connects the Australian mainland to Tasmania, with landing points at
Inverloch in Victoria and
Stanley in Tasmania. Owned and operated by Telstra, it spans 239 kilometers across the Bass Strait, a notoriously challenging waterway due to strong currents and variable weather conditions. This cable is listed as in service and has been operational since 2003, according to GeoCables data.
What makes Bass Strait-2 particularly interesting is the scarcity of publicly disclosed technical specifications about its capacity, fiber count, and supplier. While such information is often shared for large-scale international cables, it is not uncommon for domestic systems like Bass Strait-2 to have fewer details available. This lack of transparency, combined with the cable’s role in connecting Tasmania to the mainland, raises questions about its operational capabilities and redundancy in the event of outages.
Quick facts
| Name | Bass Strait-2 |
| Length | 239 km |
| Ready for Service (RFS) Year | 2003 (GeoCables database) |
| Owner | Telstra |
| Status | In service |
| Design Capacity | Not disclosed |
| Fiber Pairs | Not disclosed |
| Supplier | Not disclosed |
| Landing Points | Inverloch (Australia), Stanley (Australia) |
| Same Family Systems | Bass Strait-1 |
Route
Bass Strait-2 spans the Bass Strait, a body of water separating mainland Australia from Tasmania. Its northern landing point is Inverloch, a coastal town in Victoria known for its beaches and proximity to Melbourne. The southern landing point is Stanley, a historic town in Tasmania located on the northwestern coast. This routing enables Tasmania to connect directly to mainland Australia’s telecommunications infrastructure, facilitating internet and data services for the island state.
The Bass Strait is a challenging corridor for submarine cables due to its dynamic marine environment. Strong currents, variable seabed topography, and frequent storms require careful survey and planning during cable deployment. Standard industry practices for laying submarine cables include detailed seabed surveys using sonar and remotely operated vehicles (ROVs), careful selection of cable routes to avoid hazards, and burying the cable to protect it from anchors, fishing gear, and other risks. Repairs in this region can be complex due to weather conditions and the need for specialized repair vessels.
Why it was built and what it carries
Bass Strait-2 was built to provide additional connectivity between Tasmania and mainland Australia, supplementing the earlier Bass Strait-1 cable. Tasmania relies on submarine cables for its telecommunications links to the rest of the country, making systems like Bass Strait-2 essential for internet, voice, and data traffic. Although Telstra has not disclosed the cable’s design capacity, it is reasonable to assume that it supports significant bandwidth to meet the needs of Tasmanian residents, businesses, and government services.
History: what can be established
GeoCables data lists the cable as ready for service in 2003. However, it is worth noting that public industry sources sometimes report discrepancies in commissioning dates for submarine cables. These discrepancies could arise from differences in defining the RFS date (e.g., physical deployment vs. commercial activation), delayed announcements, or conflicting records. Without additional documentation from Telstra, the GeoCables date remains the most reliable source.
Capacity and technology
Publicly available data does not confirm the design capacity, number of fiber pairs, or specific technology used in Bass Strait-2. Without operator disclosures, attributing these values would be speculative. Submarine cables typically employ dense wavelength division multiplexing (DWDM) technology to maximize capacity, but whether Bass Strait-2 uses this or another system remains unknown.
Latency: the physics
Theoretical latency for the 239 km wet segment is approximately 1.2 milliseconds one-way, or 2.3 milliseconds round-trip, based solely on light propagation in fiber. Real-world latency is higher due to land-based infrastructure, terminal equipment, and routing. GeoCables live measurements from remote probes show significantly longer end-to-end round-trip times, such as 12.5 milliseconds between Sydney and Inverloch. These measurements reflect the full internet path rather than the cable itself, including routing inefficiencies and additional network hops.
Redundancy: what happens if it breaks
If Bass Strait-2 experiences a fault, redundancy is provided by Bass Strait-1, its predecessor in the same corridor. However, the two cables share similar geographic vulnerabilities, as both traverse the Bass Strait. Repairs to submarine cables typically involve mobilizing specialized cable ships equipped with ROVs to locate and retrieve the damaged section, followed by splicing or replacing the affected segment. Weather conditions in the Bass Strait could delay repair operations, highlighting the importance of maintaining multiple systems for redundancy.
Bottom line
- Bass Strait-2 connects Inverloch (Victoria) to Stanley (Tasmania) over 239 km.
- Owned by Telstra and listed as in service since 2003.
- Design capacity, fiber pairs, supplier, and technology are not publicly disclosed.
- Provides redundancy alongside Bass Strait-1.
- Latency measurements reflect full internet paths, not the cable itself.