Lake Tanganyika: A Submarine Cable in the Heart of Africa
The Lake Tanganyika submarine cable is a 370-kilometer fiber optic system connecting
Kalemie and
Uvira, both located within the Democratic Republic of Congo (DRC). Owned by Bandwidth and Cloud Services (BCS), the cable is listed as in service, with a recorded ready-for-service (RFS) year of 2025 in the GeoCables database. This cable is notable for its location in Lake Tanganyika, one of the world's largest freshwater lakes, and its role in improving connectivity in the region. However, several technical and operational details, including its design capacity and fiber pair count, remain undisclosed in public sources.
What makes the Lake Tanganyika cable particularly interesting is its geographical significance. Lake Tanganyika is a natural corridor that cuts through multiple countries in East and Central Africa, offering a unique opportunity for submarine cable deployment in a freshwater environment. Despite its relatively short length compared to oceanic cables, the cable plays a role in bridging connectivity gaps within the DRC, a country with historically limited telecommunications infrastructure.
Quick facts
| Cable name | Lake Tanganyika |
| Length (km) | 370 |
| Ready-for-service (RFS) | 2025 (GeoCables database value) |
| Owners | Bandwidth and Cloud Services (BCS) |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing points | Kalemie (Dem. Rep.), Uvira (Dem. Rep.) |
Route
The Lake Tanganyika cable runs entirely within the Democratic Republic of Congo, connecting Kalemie, located on the western shore of Lake Tanganyika, to Uvira, situated further north along the same shore. Lake Tanganyika itself is a prominent geographical feature, shared by multiple countries, including Burundi, Tanzania, and Zambia. However, this cable's route is confined to the DRC, leveraging the lake's natural underwater corridor to provide connectivity between these two cities.
Why it was built and what it carries
The primary purpose of the Lake Tanganyika cable is to enhance telecommunications infrastructure in the DRC, a country where terrestrial connectivity is often limited due to challenging geography and economic constraints. By utilizing the lake as a submarine cable corridor, BCS aims to provide more reliable and faster internet services to the region. While specific details about the cable's traffic and capacity are not publicly disclosed, it is reasonable to assume that it supports data transmission for both local ISPs and international connectivity, given its strategic location.
History: what can be established
The GeoCables database lists the cable's ready-for-service year as 2025. However, as of now, public sources do not offer alternative dates or conflicting information about its operational timeline. The cable is listed as in service, suggesting that deployment and commissioning have been completed. If the 2025 RFS date is accurate, it would imply that the cable was brought online relatively recently, making it a new addition to the region's telecommunications infrastructure.
Capacity and technology
No information about the cable's design capacity, fiber pair count, or specific technology has been disclosed in publicly available sources. Without documentation from BCS or other authoritative sources, any attempt to attribute these parameters would be speculative. Given the cable's regional scope, it is likely designed to meet the needs of local and regional traffic rather than serving as a high-capacity international link.
Latency: the physics
The theoretical one-way light propagation latency for the 370-kilometer wet segment of the cable is approximately 1.8 milliseconds, with a round-trip time (RTT) floor of about 3.6 milliseconds. However, real-world latency is higher due to factors such as land-based network tails, terminal equipment, and routing inefficiencies.
Live measurements conducted via remote probes show significantly higher RTT values for connections to Uvira. For example:
- Tbilisi -> Uvira: minimum RTT 196.0 ms
- Sao Paulo -> Uvira: minimum RTT 376.5 ms
- Cape Town -> Uvira: minimum RTT 92.1 ms
These figures reflect the combined latency of the cable, terrestrial networks, and internet routing, rather than the cable's intrinsic performance.
Redundancy: what happens if it breaks
If the Lake Tanganyika cable were to experience a fault, redundancy within the region would likely depend on terrestrial networks or other submarine cables in East Africa. However, the DRC's connectivity options are limited compared to neighboring countries like Kenya or Tanzania, which have access to multiple high-capacity submarine cables along the Indian Ocean. Repairing a fault in a freshwater environment like Lake Tanganyika would involve standard industry practices, including cable surveys, fault localization, and deployment of specialized vessels or divers.
Bottom line
- The Lake Tanganyika cable spans 370 kilometers within the DRC, connecting Kalemie and Uvira.
- Owned by Bandwidth and Cloud Services (BCS), it is listed as in service, with an RFS year of 2025 recorded in GeoCables.
- Design capacity, fiber pairs, supplier, and technology remain undisclosed in public sources.
- Theoretical latency for the wet segment is approximately 1.8 ms one-way, though real-world RTT is significantly higher.
- Redundancy options in the region are limited, and repairs would follow standard submarine cable practices.