Prat: A Submarine Cable Connecting Chile's Coast
The Prat submarine cable is a 3,500-kilometer fiber-optic system connecting multiple landing points along Chile's extensive Pacific coastline. Owned by Grupo Gtd, a prominent Chilean telecommunications provider, the cable was recorded as ready for service in 2020 according to GeoCables data. It is listed as currently in service, providing connectivity to key coastal cities and towns from
Puerto Montt in the south to
Arica in the north.
What makes Prat particularly interesting is its role in Chile's domestic connectivity. Unlike many submarine cables that focus on international links, Prat exclusively serves Chilean territory, connecting 12 landing points. However, several technical parameters-such as design capacity, fiber pair count, and supplier-are not publicly disclosed, leaving some aspects of its technical profile unclear.
Quick facts
| Cable name | Prat |
| Length | 3,500 km |
| Ready for service | 2020 (GeoCables database) |
| Owners | Grupo Gtd |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing points | Antofagasta, Arica, Caldera, Cartagena, Constitución, Iquique, La Serena, Puerto Montt, Puerto Saavedra, San Pedro de la Paz, Tocopilla, Valparaíso (Chile) |
Route
Prat spans Chile's Pacific coastline, connecting 12 landing points that include major urban centers such as Valparaíso and Antofagasta, as well as smaller towns like Constitución and Tocopilla. The cable's endpoints are Arica in the north, near Chile's border with Peru, and Puerto Montt in the south, a gateway to the country's Patagonian region. This route is notable for its focus on domestic connectivity, enabling strong communication within Chile without extending internationally.
Several of Prat's landing points also host other submarine cables. For example, Arica is a landing site for
South America-1 (SAm-1) and the
South Pacific Cable System (SPCS)/Mistral, while Valparaíso connects to
Curie,
Halaihai, SAm-1,
South American Crossing (SAC), and SPCS/Mistral. Puerto Montt is linked to
Fibra Optica Austral, a regional cable serving southern Chile.
Why it was built and what it carries
Prat was built to enhance domestic connectivity along Chile's elongated geography, which spans over 4,000 kilometers from north to south. The cable provides high-speed internet and data services to coastal cities and towns, supporting both residential and commercial users. Its deployment reflects Grupo Gtd's strategy to strengthen Chile's digital infrastructure, particularly in regions where terrestrial fiber networks may be limited due to challenging terrain.
While the cable's specific design capacity has not been disclosed, it is likely configured to meet the growing demand for bandwidth in Chile, driven by increasing internet usage, cloud services, and digital transformation initiatives.
History: what can be established
GeoCables records the Prat cable as ready for service in 2020. This date aligns with Grupo Gtd's expansion efforts in recent years, but public sources do not provide additional documentation or announcements confirming the exact timeline. If industry sources suggest a different RFS year, it would be important to investigate potential discrepancies, such as delays in commissioning or differences in reporting standards.
Capacity and technology
Publicly available data does not disclose Prat's design capacity, fiber pair count, or supplier. Without operator documentation, attributing specific technological features would be speculative. However, as a modern submarine cable, Prat likely employs wavelength-division multiplexing (WDM) technology to maximize data throughput. Its capacity would depend on the number of fiber pairs and the spectral efficiency of the equipment used.
Latency: the physics
Theoretical one-way light propagation over Prat's 3,500-kilometer length is approximately 17.2 milliseconds, with a round-trip time (RTT) floor of 34.3 milliseconds. These calculations assume light travels through fiber at speeds between 200,000 and 204,000 kilometers per second. Real-world latency would be higher due to factors such as land tails, terminal equipment, and routing inefficiencies. No live measurements are currently available for this cable, so its actual performance cannot be verified.
Redundancy: what happens if it breaks
If Prat experiences a failure, redundancy would depend on alternative cables serving its landing points. For example, Arica is connected to SAm-1 and SPCS/Mistral, while Valparaíso has links to multiple systems, including Curie and SAC. Puerto Montt is served by Fibra Optica Austral, which could provide backup connectivity for southern Chile. Repairing submarine cables typically involves deploying specialized vessels to locate, retrieve, and fix the damaged segment-a process that can take weeks depending on the fault's location and severity.
Bottom line
- Prat is a 3,500-kilometer submarine cable connecting 12 landing points along Chile's Pacific coast.
- Owned by Grupo Gtd, it was recorded as ready for service in 2020 and is currently in use.
- Key technical parameters, including design capacity, fiber pairs, and supplier, are not publicly disclosed.
- Theoretical latency floor is 34.3 ms RTT over the wet segment, but real-world performance is unknown.
- Redundancy is provided by other cables at shared landing points, such as SAm-1, SPCS/Mistral, and Fibra Optica Austral.