Scylla: a short submarine cable linking the UK and Netherlands
Scylla is a submarine telecommunications cable connecting
Ijmuiden in the Netherlands to
Lowestoft in the United Kingdom. Owned by euNetworks, the cable spans a modest length of 204 kilometers across the North Sea. Listed as in service, Scylla serves as part of the European network infrastructure, facilitating data transmission between these two landing points. Despite its relatively short distance, the cable plays a role in cross-border connectivity.
What stands out about Scylla is the limited publicly disclosed information about its technical specifications. Key details such as design capacity, number of fiber pairs, supplier, and technology remain undocumented in public sources. This lack of transparency makes it difficult to assess the cable's full capabilities. Additionally, while GeoCables records its ready-for-service (RFS) year as 2021, discrepancies in industry sources could exist, though none are noted here.
Quick facts
| Cable name | Scylla |
| Length | 204 km |
| Ready-for-service (RFS) year | 2021 (GeoCables database) |
| Owners | euNetworks |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing points | Ijmuiden (Netherlands); Lowestoft (United Kingdom) |
| Corridor alternatives | Ulysses 2 |
Route
Scylla connects Ijmuiden, a coastal town in the Netherlands, to Lowestoft, a port town in Suffolk, United Kingdom. Ijmuiden is a key hub for submarine cables in the Netherlands and also hosts Ulysses 2. Similarly, Lowestoft is a landing site for multiple cables, including
Circe North,
IOEMA,
Tampnet South, Ulysses 2, and
Zeus. The cable traverses the North Sea, which is a heavily trafficked corridor for submarine cables linking the UK with mainland Europe.
The corridor itself is geographically significant due to its relatively shallow waters and proximity to major European economic centers. While the North Sea presents challenges such as heavy shipping activity and fishing operations, it is a well-surveyed area for cable installations. Standard industry practices for laying submarine cables include seabed surveys to map the terrain, burial of the cable to protect it from anchors and trawling, and periodic maintenance to ensure operational reliability.
Why it was built and what it carries
Scylla was most likely built to meet the growing demand for low-latency connectivity between the UK and the Netherlands. Both countries are major hubs for data centers, financial institutions, and internet exchanges. By providing a direct link between Ijmuiden and Lowestoft, Scylla supports high-speed data transfer for commercial and infrastructure purposes. However, without operator documentation, attributing specific traffic types or usage patterns to the cable would be speculative.
History: what can be established
GeoCables records Scylla's ready-for-service year as 2021. This aligns with the timeline of increasing investments in European submarine cable infrastructure to accommodate rising data demands. No conflicting dates from industry sources are noted in this case, but such conflicts can arise due to delays in commissioning or discrepancies in public announcements.
Capacity and technology
Publicly available information does not disclose Scylla's design capacity, fiber pair count, supplier, or technology. Without operator documentation, these details remain unknown. Submarine cables typically employ dense wavelength division multiplexing (DWDM) to maximize data throughput, but whether Scylla uses this or other technologies cannot be confirmed.
Latency: the physics
The theoretical one-way light propagation latency for Scylla over its 204 km length is approximately 1.0 ms, with a round-trip time (RTT) floor of 2.0 ms. This calculation assumes light travels through fiber at speeds between 200,000 and 204,000 km/s. Real-world latency measurements, however, are higher due to additional factors such as land tails, terminal equipment, and routing complexities.
GeoCables' live measurements, which reflect the entire internet path rather than the cable itself, show significant variation. For example:
- Lowestoft -> Ijmuiden: min 10.2 ms, avg 25.9 ms
- Ijmuiden -> Lowestoft: min 33.6 ms, avg 36.3 ms
These values highlight the impact of terrestrial routing and network congestion.
Redundancy: what happens if it breaks
If Scylla were to experience a fault, redundancy in the corridor is provided by Ulysses 2, which also lands at Ijmuiden and Lowestoft. This alternative ensures continuity of service, albeit with potential differences in latency or capacity. Repairing submarine cables typically involves deploying specialized vessels equipped with remotely operated vehicles (ROVs) to locate and fix the fault. Repairs can be time-consuming, especially in adverse weather conditions or congested maritime areas.
Bottom line
- Scylla is a 204 km submarine cable linking Ijmuiden, Netherlands, to Lowestoft, UK.
- Owned by euNetworks, it has been recorded as ready-for-service since 2021.
- Key technical specifications such as capacity, fiber pairs, and technology are not publicly disclosed.
- Its theoretical latency floor is 2.0 ms RTT, but real-world measurements are higher due to network factors.
- Redundancy is provided by Ulysses 2, which shares the same corridor.