C-Lion1

Active

1,173 km submarine cable system, ready for service }}.

Key facts

Status: Active
Ready for service: }}
Length: 1,173 km
Design capacity: 120Tbit/s
Owner: Cinia Oy
Connects: Finland

Landing points

item1_value=1 | Hanko, Finland, item1_value=1 | Hanko — Finland
item2_value=2 | Helsinki, Finland, item2_value=2 | Helsinki — Finland
item3_value=3 | Rostock, Germany }}, item3_value=3 | Rostock

Overview

C-Lion1 crosses the Baltic Sea to provide a direct fibre connection between Finland and Germany, spanning 1,173 kilometres. The system lands at Hanko and Helsinki in Finland, and at Rostock in Germany, threading a path through one of the world's busier enclosed seas to tie Scandinavia's digital infrastructure into the broader European backbone.

Route and Regional Significance

For Finland, a country that sits at the geographic edge of Europe's core connectivity map, a dedicated submarine cable to Germany carries particular strategic weight. Overland routes between Finland and central Europe depend on transit through other nations' networks; C-Lion1 offers an alternative path that bypasses that dependency. The German landing at Rostock positions the cable to tap into onward terrestrial links running south and west across the continent, while the dual Finnish landings at Hanko and Helsinki provide redundancy and distribution options within the country.

The Baltic Sea crossing is geographically compact relative to transoceanic systems, but the sea floor environment — shallow in places, subject to heavy commercial shipping and fishing activity — demands careful routing and burial planning. The system's 1,173-kilometre length reflects a measured course through those constraints.

Ownership and Capacity

C-Lion1 is owned by Cinia Oy, a Finnish company with strong state-linked backing that has positioned itself as an independent infrastructure operator rather than a traditional carrier. That ownership structure gives the cable a character distinct from systems built by consortia of dominant telcos: Cinia has promoted C-Lion1 as open-access infrastructure, available to a range of wholesale customers rather than reserved for owner traffic.

The system is designed for 120 Tbit/s of capacity — a figure that reflects modern coherent optical technology and leaves headroom for traffic growth as demand on the Finland–Germany corridor develops.

Build

Construction contractor details are not publicly documented for this system.