Strategic Chokepoint: Marsala's Role in Global Undersea Cable Connectivity

Where This Is and Why Here

The location at coordinates 37.5° N, 12.0° E lies in the waters off the western coast of Sicily, near Marsala, where the Strait of Sicily narrows to its minimum width between the Italian island and the Tunisian shore. The navigable corridor here spans approximately 145 km, but only specific sections of the seabed are suitable for cable deployment due to depth variations, seabed topography, and heavy shipping activity. This geographical configuration makes Marsala a critical bottleneck: any submarine cable connecting the western and eastern Mediterranean, Europe and Africa, or Asia must traverse this corridor. Alternative routes would either bypass the Iberian Peninsula entirely or detour around Africa. The strait’s seabed is relatively shallow in coastal areas, with depths ranging from 50 to 400 meters. While this simplifies cable installation, it also increases vulnerability to anchors and trawling activities.

What Passes Through This Corridor

A total of 23 submarine cables converge in the Marsala area, a concentration comparable to other global chokepoints like the Red Sea or the Strait of Malacca. These include several major planetary-scale trunk lines:

• 2Africa (45,000 km): a ring system encircling Africa and linking it to Europe and the Middle East;
• FLAG Europe-Asia / FEA (28,000 km): one of the longest-operating transcontinental routes;
• AAE-1 (25,000 km): Asia Africa Europe-1, connecting Southeast Asia to Europe via the Indian Ocean and the Red Sea;
• SEA-ME-WE-5 and SEA-ME-WE-4 (20,000 km each): consortium-operated trunk lines linking Asia, the Middle East, and Western Europe;
• EIG (15,000 km): Europe India Gateway, a direct route between the UK and India;
• IMEWE (12,091 km) and IEX (9,775 km): additional Asia-Europe connections.

In addition to these trunk lines, regional systems also traverse Marsala, including Medusa (8,760 km), MENA / Gulf Bridge International (8,000 km), EMC West-1 and EMC West-2, TE North/TGN-Eurasia/SEACOM/Alexandros/Medex, Hawk, as well as local Italian systems like Unitirreno and Piano Isole Minori.

Who Would Be Affected

Simultaneous damage to multiple cables in this area would impact or degrade connectivity for at least 14 countries: Italy, Egypt, Saudi Arabia, Oman, Spain, South Africa, UAE, Algeria, Libya, Greece, Somalia, Yemen, Tunisia, and Israel. For North African nations such as Algeria, Tunisia, and Libya, Marsala is a near-exclusive route to European traffic exchange hubs, as alternative paths either traverse the same zone or require significant detours via the Atlantic. Egyptian and Israeli operators would lose portions of their western routes, though they maintain backup connections through the Red Sea. For South Africa and Somalia, disruptions would affect the capacity of 2Africa, a vital cable for East African connectivity.

Risks: From Fishermen to Geopolitics

The Strait of Sicily is among the busiest maritime corridors in the Mediterranean. Anchorage zones for vessels awaiting entry to Tunisian, Marsala, and Trapani ports overlap with cable routes. Fishing activities, particularly by Sicilian and Tunisian trawlers, occur at depths of 50-200 meters, where cables are not always deeply buried. Historically, mechanical damage from anchors and trawls has been the leading cause of cable incidents in the Mediterranean.

Seismic activity in this region is moderate but notable, as western Sicily lies along the boundary of the African and Eurasian tectonic plates. Underwater landslides triggered by earthquakes exceeding magnitude 5.5 can displace unsecured cable sections. Documented events, such as the 2003 cable breaks off Algeria, highlight this risk.

Geopolitical factors also heighten exposure. Cables passing through Marsala are operated by entities from countries with significant bilateral tensions, such as Israel and Arab states, the UAE and Yemen, or Europe and Libya. Since 2022, incidents involving underwater infrastructure in regions like the Baltic and North Seas have drawn increased attention to chokepoints like Marsala. Over the past 30 days, GeoCables monitoring identified one RTT anomaly on cables in this zone, underscoring the need for continued vigilance.

What GeoCables Monitors

GeoCables actively monitors all 23 cables passing through the Marsala zone in real time, analyzing segment delays, RTT deviations from baseline values, and abnormal routing patterns. Additionally, AIS data is integrated to flag vessels drifting or anchoring near cable routes as potential risks. The RTT anomaly recorded in the past month remains under extended observation. Until external factors such as scheduled maintenance or node congestion are confirmed as causes, this anomaly remains an active signal within the system.