Continente-Madeira: Connecting mainland Portugal to Madeira
The Continente-Madeira submarine cable links mainland Portugal with the island of Madeira, spanning approximately 1179 kilometers across the Atlantic Ocean. Owned by Altice Portugal and listed as in service, this cable plays a key role in telecommunications between the Portuguese mainland and its autonomous region of Madeira. Its landing points are located at
Carcavelos, near Lisbon, and
Funchal, the capital of Madeira.
What stands out about the Continente-Madeira cable is the scarcity of publicly disclosed information about its technical specifications, such as design capacity, fiber pairs, supplier, and technology. While the GeoCables database records its ready-for-service year as 2000, industry sources sometimes report conflicting dates for submarine cables, which will be explored further in this article.
Quick facts
| Cable name | Continente-Madeira |
| Length | 1179 km |
| Ready-for-service year | 2000 (GeoCables database) |
| Owner | Altice Portugal |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing points | Carcavelos (Portugal), Funchal (Portugal) |
| Alternatives in same corridor | New CAM Ring |
Route
The Continente-Madeira cable connects Carcavelos, a coastal town near Lisbon on mainland Portugal, to Funchal, the largest city on Madeira Island. Carcavelos is a hub for multiple submarine cables, including
2Africa,
Africa Coast to Europe (ACE),
BUGIO,
Columbus-III Azores-Portugal,
Medusa Submarine Cable System, New
CAM Ring, and
Olisipo. Similarly, Funchal hosts other cables such as CAM Ring,
EllaLink, and New CAM Ring. These landing points highlight the strategic importance of both locations in regional and international telecommunications.
Why it was built and what it carries
The cable was constructed to provide reliable telecommunications connectivity between mainland Portugal and Madeira. As Madeira is an autonomous region located over 1000 kilometers from the mainland, submarine cables like Continente-Madeira are essential for supporting internet, voice, and data services. While specific traffic volumes and types carried by the cable are not publicly disclosed, its role in linking Madeira to the mainland makes it a critical part of the region's digital infrastructure.
History: what can be established
The GeoCables database lists the Continente-Madeira cable as ready for service in the year 2000. However, industry sources occasionally report different commissioning dates for submarine cables, which can arise from discrepancies in documentation, phased deployment timelines, or updates to cable systems after their initial installation. Without operator confirmation, these alternative dates cannot be definitively attributed to this cable.
Altice Portugal, the cable's owner, is a major telecommunications operator in Portugal. The company's involvement in submarine cable systems reflects its commitment to maintaining connectivity between mainland Portugal and its islands.
Capacity and technology
Publicly available data does not disclose the design capacity, fiber pair count, supplier, or specific technology used in the Continente-Madeira cable. This lack of transparency is not uncommon for older submarine cables, especially those serving regional routes rather than major international corridors. Without operator documentation, attributing specific technical details would be speculative.
Latency: the physics
The computed one-way light propagation latency for the Continente-Madeira cable is approximately 5.8 milliseconds over its 1179 km length. This corresponds to a theoretical round-trip time (RTT) floor of 11.6 milliseconds for the wet segment alone, assuming light travels at 200,000 to 204,000 km/s in optical fiber. Real-world latency measurements would be higher due to additional factors such as land-based network tails, terminal equipment processing, and routing inefficiencies. No live latency measurements for this cable are currently available.
Redundancy: what happens if it breaks
If the Continente-Madeira cable were to experience a fault, redundancy is provided by the New CAM Ring cable, which also connects Carcavelos and Funchal. This alternative ensures continued connectivity between mainland Portugal and Madeira. Repairing submarine cables typically involves deploying specialized cable ships equipped with tools to locate, retrieve, and fix the damaged sections. The repair process can be time-consuming, depending on weather conditions, the depth of the cable, and the nature of the fault.
Bottom line
- The Continente-Madeira cable spans 1179 km, linking Carcavelos (mainland Portugal) to Funchal (Madeira).
- Owned by Altice Portugal, it has been listed as in service since 2000 (GeoCables database).
- Technical specifications such as design capacity, fiber pairs, supplier, and technology are not publicly disclosed.
- Its theoretical round-trip latency floor is 11.6 ms for the wet segment, but real-world latency would be higher.
- Redundancy is provided by the New CAM Ring cable, which shares the same landing points.