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BCS North - Phase 1

In Service

513 km · 5 Landing Points · 2 Countries · Ready for Service: 1998

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Specifications

Length513 km
StatusIn Service
Ready for Service1998
Landing Points5
Countries2

Owners

Arelion

Landing Points (5)

Location Country Position
Hanko, Finland FI Finland 59.8232°, 22.9682°
Haradsholm, Finland FI Finland 60.3010°, 22.3021°
Helsinki, Finland FI Finland 60.1711°, 24.9325°
Mariehamn, Finland FI Finland 60.1138°, 19.9379°
Stavsnas, Sweden SE Sweden 59.2928°, 18.6883°

If this cable is cut

What each country and landing point keeps if BCS North - Phase 1 goes down. A calculation from our cable and landing-point database, not a forecast.

CountryOther international cablesLand linksWhat remains
Finland14 yes reserve of 14 cables
Sweden26 yes reserve of 26 cables

Landing points with no other cable nearby

  • Haradsholm, Finland: no other cable lands within 50 km.

On an island this means losing the submarine link; on the mainland traffic can still go over land.

No alerts from our monitoring on this cable in the last 180 days. Events feed →

Counted: other international cables landing in the same country (domestic cables between points of one country are not a way out), other cables at landing points within 50 km, and whether the country has land links. Not counted: cable capacity, operator contracts and satellite. Use as a first look at dependence, not as a statement of what would happen.

Live Performance

197
measurements
13
probes
221
days monitored
50.1
ms avg RTT
2
anomalies

Monitored from 2026-03-10 through 2026-10-17 - live ICMP round-trip time measurements via our monitoring probes. All values below are recomputed daily from raw probe data.

Measurement sources

Probe Location Samples Avg Min-Max Last seen
#40 control probe 78 48.6 ms 3.1-101.7 2026-10-17
#27955 control probe 28 9.5 ms 9.2-10.0 2026-10-09
#258 control probe 24 29.8 ms 18.6-62.4 2026-04-09
#3283 control probe 16 17.5 ms 15.2-20.0 2026-08-23
own probe Minsk BY 13 39.8 ms 19.9-52.9 2026-09-03
#6427 own probe Sydney AU 11 269.2 ms 262.7-273.4 2026-09-03
own probe Saint Petersburg RU 10 12.8 ms 9.3-17.1 2026-09-03
#911 control probe 8 77.0 ms 23.6-103.1 2026-05-25
own probe Almaty KZ 2 76.2 ms 76.2-76.2 2026-04-17
own probe Tbilisi GE 2 73.7 ms 73.7-73.8 2026-04-17
own probe Jerusalem IL 2 81.6 ms 81.4-81.9 2026-04-17
own probe Sevastopol UA 2 49.4 ms 49.0-49.7 2026-04-17
own probe Moscow RU 1 21.7 ms 21.7-21.7 2026-07-22

About the BCS North - Phase 1 Cable System

BCS North - Phase 1: Arelion's submarine link in the Baltic Sea

BCS North - Phase 1 is a submarine cable system connecting Finland and Sweden across the Baltic Sea. It spans 513 kilometers and was recorded as ready for service in 1998 according to GeoCables data. Owned by Arelion, the cable is listed as currently in service and forms part of a broader family system that includes BCS North - Phase 2. What makes this cable notable is the density of alternative systems in its landing locations, particularly Helsinki and Hanko, which host connections to numerous other cables. Despite its established presence, several technical details about BCS North - Phase 1, such as its design capacity, fiber pair count, supplier, and specific technology, remain undisclosed in publicly available sources.

Quick facts

NameBCS North - Phase 1
Length513 km
Ready for Service (RFS)1998 (GeoCables database)
OwnerArelion
StatusIn service
Design CapacityNot disclosed
Fiber PairsNot disclosed
SupplierNot disclosed
TechnologyNot disclosed
Landing PointsHanko, Haradsholm, Helsinki, Mariehamn (Finland); Stavsnas (Sweden)

Show BCS North - Phase 1 on the interactive cable map

Route

BCS North - Phase 1 connects five landing points, four in Finland (Hanko, Haradsholm, Helsinki, Mariehamn) and one in Sweden (Stavsnas). These locations are strategically positioned along the Baltic Sea, a region known for its dense submarine cable infrastructure. Hanko and Helsinki, in particular, are hubs for numerous other systems, including C-Lion1, Eastern Light Sweden-Finland I and II, and Finland-Estonia connections. The corridor between Finland and Sweden is a significant link for telecommunications in the Nordic region, providing connectivity between two technologically advanced nations. The cable's landing points suggest it was designed to integrate seamlessly into the broader Baltic Sea network.

Why it was built and what it carries

BCS North - Phase 1 was likely built to enhance connectivity between Finland and Sweden, two countries with strong economic and technological ties. The cable may serve as a key route for internet traffic, enterprise communications, and data center interconnections in the region. However, the specific traffic it carries and its role within Arelion's broader network are not publicly detailed. Given the presence of numerous alternative cables at its landing points, BCS North - Phase 1 is part of a highly redundant corridor. This redundancy is essential for maintaining reliable connectivity in the event of cable outages or maintenance activities.

History: what can be established

GeoCables records the cable's ready-for-service date as 1998. If industry sources suggest a different year, this discrepancy could arise from delays in documentation, phased activation of segments, or updates to the cable's operational status post-installation. Without corroborating data, the 1998 date remains the most reliable reference. The cable's operational history, including any upgrades or repairs, is not publicly documented. Its continued listing as "in service" suggests it remains functional and integrated into Arelion's network.

Capacity and technology

Public sources do not disclose the design capacity, fiber pair count, supplier, or specific technology of BCS North - Phase 1. Without operator documentation, attributing these details would be speculative. It is likely that the cable has undergone upgrades since its initial deployment, as is standard practice for submarine systems to meet evolving bandwidth demands.

Latency: the physics

The theoretical one-way light propagation latency over BCS North - Phase 1's 513 km wet segment is approximately 2.5 milliseconds, with a round-trip time (RTT) floor of 5.0 milliseconds. Real-world latency measurements, however, are higher due to additional factors such as terrestrial routing, terminal equipment, and network congestion. GeoCables' live remote probes provide some insight into end-to-end latency, but these measurements reflect the full internet path rather than the cable itself. For example, the minimum measured RTT between Stavsnas and Helsinki is reported as 1.6 milliseconds, which is below the theoretical floor and therefore a measurement artifact. The average RTT for this route is 34.5 milliseconds, indicating significant contributions from external network factors. Similarly, other routes, such as Minsk to Helsinki (average RTT 51.9 ms), include latency from terrestrial segments and intermediate routing.

Redundancy: what happens if it breaks

If BCS North - Phase 1 were to experience an outage, the Baltic Sea region's dense cable network offers numerous alternatives. At Hanko, other systems like C-Lion1 and Eastern Light Sweden-Finland I and II could potentially reroute traffic. Helsinki, a major hub, hosts connections to over seven other cables, including Baltic Sea Submarine Cable and Finland-Estonia systems. Stavsnas connects to Sweden-Estonia (EE-S 1), providing additional redundancy. Repair logistics for submarine cables typically involve deploying specialized cable ships equipped with remotely operated vehicles (ROVs) to locate and fix faults. Repairs can take weeks depending on weather conditions, the nature of the damage, and the availability of repair vessels.

Bottom line

  • BCS North - Phase 1 is a 513 km submarine cable linking Finland and Sweden across the Baltic Sea.
  • Owned by Arelion, the cable has been in service since 1998, according to GeoCables data.
  • Technical details such as design capacity, fiber pairs, supplier, and technology are not publicly disclosed.
  • Theoretical latency over the wet segment is approximately 5.0 ms RTT, but real-world measurements are higher due to additional network factors.
  • Redundancy is strong in this corridor, with numerous alternative cables at key landing points.
  • Publicly available information about the cable's upgrades, operational history, and traffic profile is scarce.

What next: Explore BCS North - Phase 1 on the interactive submarine cable map, browse the full catalog of submarine cables, or follow live network events and real-world internet latency.

Health

Status✓ Normal
RTT74.78 ms / base 10.26 ms
Last checked2026-10-17 20:31

Monitored by our probe network. Open monitoring →

RTT History

Route: #40 → Helsinki Measured: 2026-10-17 20:31
74.8 ms
Min Avg Max #
7 days 9.6 31.6 74.8 6
30 days 9.6 36.3 74.8 10
60 days 3.1 48.6 101.7 78

Health Timeline

Fri, Sep 4
View full event log →
Hop Anomaly
26ms → 93ms (3.51×)
03:30
Sat, Aug 1
View full event log →
Hop Anomaly
4ms → 32ms (7.94×)
19:01
Thu, Jul 23
View full event log →
Hop Anomaly
4ms → 21ms (5.80×)
03:03
Sun, Jul 12
View full event log →
Hop Anomaly
6ms → 29ms (4.84×)
08:00
Fri, Jun 12
View full event log →
Hop Anomaly
6ms → 73ms (11.83×)
05:00
Thu, Jun 4
View full event log →
Hop Anomaly
5ms → 224ms (46.39×)
23:00
Wed, May 27
View full event log →
Hop Anomaly
6ms → 237ms (40.23×)
03:00
Tue, May 19
View full event log →
Hop Anomaly
93ms → 286ms (3.05×)
19:00
Fri, May 15
View full event log →
Hop Anomaly
4ms → 35ms (8.89×)
13:00
Sat, Apr 18
View full event log →
Helsinki
RTT Spike
46ms → 102ms (2.23×)
02:31
Fri, Apr 17
View full event log →
Helsinki
Resolved
39ms → 13ms
20:31
Helsinki
Improving
39ms → 48ms
20:00
Helsinki
Alert Created
39ms → 92ms (2.37×)
19:02
Helsinki
Anomaly Confirmed
39ms → 92ms (2.37×)
19:02
Helsinki
RTT Spike
39ms → 92ms (2.37×)
19:02
Helsinki
RTT Spike
35ms → 92ms (2.63×)
18:32
Hop Anomaly
20ms → 795ms (39.06×)
18:30
Helsinki
Resolved
37ms → 10ms
16:31
Helsinki
Improving
37ms → 12ms
16:00
Helsinki
Alert Created
37ms → 81ms (2.17×)
15:01
Helsinki
Anomaly Confirmed
37ms → 81ms (2.17×)
15:01
Helsinki
RTT Spike
37ms → 81ms (2.17×)
15:01
Helsinki
RTT Spike
36ms → 74ms (2.07×)
14:31
Sat, Apr 11
View full event log →
Hop Anomaly
5ms → 91ms (16.90×)
23:00
Sat, Apr 4
View full event log →
Hop Anomaly
6ms → 51ms (8.56×)
19:00

Incident history

Significant latency incidents our probes detected on this cable, each with its own report.

All cable incidents →

FAQ

What is the length of the BCS North - Phase 1 cable?
The BCS North - Phase 1 submarine cable is 513 km long.
Which countries does BCS North - Phase 1 connect?
BCS North - Phase 1 connects 2 countries via 5 landing points.
Who owns the BCS North - Phase 1 cable?
BCS North - Phase 1 is owned by a consortium including Arelion.
When was BCS North - Phase 1 put into service?
The BCS North - Phase 1 cable entered service in 1998.
BCS North - Phase 1
  • Length513 km
  • StatusIn Service
  • Ready for Service1998

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