Monitored from 2026-03-28 through 2026-08-15 - live ICMP round-trip time measurements via our monitoring probes. All values below are recomputed daily from raw probe data. ✓ No anomalies detected in the monitored period.
Measurement sources
Probe
Location
Samples
Avg
Min-Max
Last seen
#61861
control probe
208
24.5 ms
19.1-151.8
2026-08-15
#6427 own probe
Sydney AU
10
274.0 ms
266.7-283.3
2026-07-16
#1014473 own probe
Minsk BY
10
47.8 ms
43.0-69.2
2026-07-16
#1016031 own probe
Kyiv UA
10
52.1 ms
49.2-58.2
2026-07-16
#1008530
control probe
5
25.5 ms
24.7-27.0
2026-07-16
About the UK-Channel Islands-7 Cable System
UK-Channel Islands-7: An Established Submarine Cable Link
The UK-Channel Islands-7 is a submarine telecommunications cable connecting the United Kingdom and Guernsey in the Channel Islands. It spans 124 kilometers and has been in service since 1994, according to GeoCables database records. Owned jointly by BT and Sure, the cable is a critical part of the region's connectivity infrastructure, linking L'Ancresse Bay in Guernsey to Stoke Fleming in the United Kingdom.
What stands out about UK-Channel Islands-7 is the limited public disclosure concerning its technical specifications, such as design capacity, fiber pair count, and supplier details. Additionally, the cable operates in a corridor with redundancy provided by the Channel Islands-9 Liberty Submarine Cable, which lands at both endpoints. This redundancy is significant for ensuring uninterrupted service in case of outages.
Quick facts
Cable name
UK-Channel Islands-7
Length
124 km
Ready-for-service year
1994 (GeoCables database)
Owners
BT, Sure
Status
In service
Design capacity
Not disclosed
Fiber pairs
Not disclosed
Supplier
Not disclosed
Technology
Not disclosed
Landing points
L'Ancresse Bay (Guernsey); Stoke Fleming (United Kingdom)
The UK-Channel Islands-7 connects Stoke Fleming on the southern coast of England to L'Ancresse Bay in Guernsey, one of the Channel Islands. Guernsey is situated in the English Channel, closer to France than to mainland Britain, making this cable an essential link for the island's telecommunication needs. Both landing points are shared with the Channel Islands-9 Liberty Submarine Cable, which provides redundancy in the same corridor.
Why it was built and what it carries
The cable was likely constructed to enhance connectivity between the Channel Islands and mainland Britain, supporting the growing demand for reliable telecommunications in the early 1990s. While specific data about its capacity or traffic types is not publicly disclosed, it is reasonable to assume that the cable carries a mix of voice, data, and internet traffic, serving both residential and business users in Guernsey and the UK.
History: what can be established
The GeoCables database lists the cable's ready-for-service year as 1994. While no conflicting information has been identified in industry sources, the lack of detailed historical documentation means that specific milestones, such as construction timelines or upgrades, remain unclear. The cable's continued operation suggests that it has been maintained effectively by its owners, BT and Sure.
Capacity and technology
Publicly available data does not confirm the design capacity, fiber pair count, or specific technological features of UK-Channel Islands-7. Without documentation from the operators, attributing these details would be speculative. Given its age, the cable may have undergone upgrades to remain compatible with modern telecommunications demands, but this cannot be stated without evidence.
Latency: the physics
The theoretical one-way light propagation time over the 124 km wet segment is approximately 0.6 milliseconds, with a round-trip time (RTT) floor of 1.2 milliseconds. However, live measurements conducted via remote probes show significantly higher RTTs, reflecting the impact of land-based routing, terminal equipment, and network congestion. For example:
L'Ancresse Bay -> Stoke Fleming: minimum 19.1 ms, average 24.6 ms
Stoke Fleming -> L'Ancresse Bay: minimum 24.7 ms, average 25.5 ms
These values demonstrate the difference between theoretical cable latency and real-world internet performance, which includes additional network components beyond the submarine segment.
Redundancy: what happens if it breaks
In the event of a failure, redundancy is provided by the Channel Islands-9 Liberty Submarine Cable, which also connects L'Ancresse Bay and Stoke Fleming. This alternative ensures that connectivity between Guernsey and the UK can be maintained. Repairs to submarine cables typically involve locating the fault using specialized equipment, deploying cable ships, and conducting splicing or replacement operations. These processes can take days to weeks, depending on the nature of the fault and weather conditions.
Bottom line
UK-Channel Islands-7 is a 124 km submarine cable connecting Guernsey and the UK.
It has been in service since 1994, according to GeoCables records.
Owned by BT and Sure, its technical specifications are not publicly disclosed.
Redundancy is provided by the Channel Islands-9 Liberty Submarine Cable.
Live latency measurements show higher RTTs than the theoretical floor due to additional network factors.