High-capacity Undersea Guernsey Optical-fibre (HUGO) cable: latency up to 2.5× normal, 6 Aug 2026
What we measured
| Cable | High-capacity Undersea Guernsey Optical-fibre (HUGO) |
| Segment | Porthcurno, GB → Saints Bay, GG |
| Detected | 2026-08-06 21:02 UTC |
| Resolved | 2026-08-07 00:01 UTC |
| Duration | 2h 59m |
| Observed latency | 28.2 ms |
| Baseline | 47.6 ms · 2.52× |
| Increase | +152% |
| Severity | warning |
Who is affected
Countries where High-capacity Undersea Guernsey Optical-fibre (HUGO) 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 |
|---|---|---|---|
| France resilience index: 100 · resilient |
1 of 35 cables (3% of submarine diversity) | 2Africa, Africa Coast to Europe (ACE), Africa-1 +31 more | median 67 ms today vs 71 ms over 30 days (666 routes) - unchanged |
| Guernsey resilience index: 53 · vulnerable |
1 of 5 cables (20% of submarine diversity) | Channel Islands-9 Liberty Submarine Cable, Guernsey-Jersey-4, 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. Other measurements did not confirm the event. We treat this as a probable false positive and label it as such.
Timeline
- Alert 2026080601: warning - ratio 2.52x
- Alert #167 improving: 1/3 consecutive OK
- Alert #167 improving: 2/3 consecutive OK
- Alert #167 resolved: RTT 28.2ms (baseline 47.56ms), 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.