Channel Islands-9 Liberty Submarine Cable: latency up to 2.5× normal, 20 Jul 2026
What we measured
| Cable | Channel Islands-9 Liberty Submarine Cable |
| Segment | L'Ancresse Bay, GG → Stoke Fleming, GB |
| Detected | 2026-07-20 11:31 UTC |
| Resolved | 2026-07-21 11:31 UTC |
| Duration | 1d 0h |
| Observed latency | 22.4 ms |
| Baseline | 22.6 ms · 2.45× |
| Increase | +145% |
| Severity | warning |
Who is affected
Countries where Channel Islands-9 Liberty Submarine Cable comes ashore, how much of their submarine diversity this cable represents, and what our measurements into them show.
| Country | Dependence on this cable | Other submarine cables | What the measurements show |
|---|---|---|---|
| Guernsey resilience index: 53 · vulnerable |
1 of 5 cables (20% of submarine diversity) | Guernsey-Jersey-4, High-capacity Undersea Guernsey Optical-fibre (HUGO), INGRID +1 more | no measurement today; median 79 ms over 30 days (18 routes) |
| United Kingdom resilience index: 100 · resilient |
1 of 68 cables (1% of submarine diversity) | 2Africa, Amitie, Apollo +64 more | median 103 ms today vs 74 ms over 30 days (1011 routes) - slower |
Dependence is structural (share of the country's submarine cables), not a traffic share: real traffic distribution across cables is not public.
Path analysis
Traffic kept the same route. Latency rose without a visible path change, which points at congestion or a fault on the existing route rather than a reroute.
Cross-probe verdict. Too few independent vantage points were watching this endpoint to reach a cross-probe verdict.
Timeline
- Alert 2026072003: warning - ratio 2.45x
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 2/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 2/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 2/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 2/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 2/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 1/3 consecutive OK
- Alert #155 improving: 2/3 consecutive OK
- Alert #155 resolved: RTT 22.41ms (baseline 22.64ms), 3 consecutive OK
Detection method
Latency is sampled continuously from our probe network. An alert opens when round-trip time to a monitored endpoint holds above its rolling baseline, and closes automatically once it returns. Full method is described on the methodology page.