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

Where This Is and Why Here

The location with coordinates 37.5° N, 12.0° E is the waters off the western coast of Sicily, near the city of Marsala, where the Strait of Sicily narrows to its minimum between the Italian island and the Tunisian shore. The width of the navigable corridor here is about 145 km, but only part of the seabed is suitable for laying cables, taking into account depths, seabed topography and zones of intense shipping activity. This geometry makes Marsala a bottleneck: any cable connecting the western and eastern Mediterranean, Europe and Africa, or Asia must physically pass through this corridor. There is no alternative route that does not either bypass the entire Iberian Peninsula or detour around Africa. The seabed of the strait is relatively shallow in coastal areas, ranging from 50 to 400 meters. On one hand, this simplifies cable laying, but on the other, it makes the cables vulnerable to anchors and trawls.

What Passes Through This Corridor

A total of 23 submarine cables converge in the Marsala area, a concentration comparable to the Red Sea or the Strait of Malacca. Among them are several planetary-scale trunk lines:

• 2Africa (45,000 km): a ring cable encircling Africa and connecting it to Europe and the Middle East;
• FLAG Europe-Asia / FEA (28,000 km): one of the oldest operational transcontinental routes;
• AAE-1 (25,000 km): Asia Africa Europe-1, linking 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 trunk lines between Asia, the Middle East and Western Europe;
• EIG (15,000 km): Europe India Gateway, a direct line between the United Kingdom and India;
• IMEWE (12,091 km) and IEX (9,775 km): additional Asia-Europe routes.

In addition to the trunk lines, regional systems pass through Marsala: 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 purely local Italian systems like Unitirreno and Piano Isole Minori.

Who Would Be Affected

If multiple cables in this area were simultaneously damaged, at least 14 countries would lose traffic or experience degradation: Italy, Egypt, Saudi Arabia, Oman, Spain, South Africa, UAE, Algeria, Libya, Greece, Somalia, Yemen, Tunisia and Israel. For North African countries like Algeria, Tunisia and Libya, Marsala is practically the only route to European traffic exchange hubs: alternative routes either pass through the same zone or require a detour via the Atlantic. Egyptian and Israeli operators would lose part of their western routes, although they have backup exits through the Red Sea. For South Africa and Somalia, a break would mean losing part of the capacity of 2Africa, a cable that often serves as the primary connection for East African countries.

Risks: From Fishermen to Geopolitics

The Strait of Sicily is one of the busiest shipping corridors in the Mediterranean. Anchorage zones for ships waiting to enter the ports of Tunisia, Marsala and Trapani overlap with cable routes. Fishing vessels, especially Sicilian and Tunisian trawlers, operate at depths of 50-200 meters, where cables are not always sufficiently buried. Historically, mechanical damage from anchors and trawls accounts for the majority of incidents in the Mediterranean.

Seismic activity in this area is moderate but not negligible: western Sicily lies on the boundary of the African and Eurasian tectonic plates. Underwater landslides triggered by earthquakes with magnitudes above 5.5 can displace unsecured cable segments. Documented precedents of such events in the Mediterranean include a series of breaks off the coast of Algeria in 2003.

Another issue is geopolitical exposure. Cables passing through Marsala are operated by companies and consortia representing countries with sharp bilateral tensions: Israel and Arab states, UAE and Yemen, Europe and Libya. With the growing number of incidents involving underwater infrastructure in the Baltic and North Seas since 2022, such chokepoints are attracting increased attention from intelligence services. Over the past 30 days, monitoring has detected one RTT anomaly on cables in this zone, a signal that requires ongoing observation.

What GeoCables Monitors

In real time, the platform monitors all 23 cables passing through the Marsala zone: segment delays, RTT deviations from baseline values and the emergence of abnormal routing patterns. An additional layer involves AIS data: vessels drifting or anchoring in close proximity to cable routes are flagged as potential risks. The RTT anomaly recorded in the past month is under extended observation: as long as it is not explained by external factors (scheduled maintenance, node congestion), it remains an open signal in the system.