Undersea Cables Risk Report Q1 2026

Surveillance & Physical Threat Activity Around Global Telecommunication Cable Infrastructure

Undersea cables (also referred to as subsea, submarine, and underwater cables) carry the vast majority of global internet and communications traffic, forming a critical layer of international digital infrastructure. As geopolitical tensions rise and maritime activity intensifies around strategic cable corridors, monitoring vessel behavior near cable routes has become increasingly important for understanding potential risks to cable security and resilience.

The Undersea Cables Risk Report is a quarterly data-driven report examining vessel activity conducted in proximity to global undersea cable infrastructure. The report focuses on two primary categories of risk: intentional slow-speed activity by service and research vessels that may indicate cable surveying, mapping, or surveillance behavior, and physical risk posed by fishing and trawling activity capable of damaging subsea infrastructure.

Using global maritime activity data from Q1 2026, this report identifies the regions, vessel types, and flag states most frequently associated with cable-proximate operations, highlights geographic hotspots and emerging operational patterns, and establishes a baseline for tracking changes in cable-related maritime risk over time.

Key Findings

• The Indian Ocean emerged as the primary global hotspot for cable-proximate vessel activity, driven by concentrated Iranian and Chinese operations around the Arabian Sea and Oman corridor.
• Chinese survey and research vessels conducted repeated slow-speed activity above strategic cable corridors, including operations near the SMW5, FALCON, EIG, and AAE-1 systems.
• Physical cable exposure remained highest in trawling-heavy regions including the Mediterranean, North Atlantic, and North Sea cable corridors, where prolonged fishing activity intersected dense subsea infrastructure networks.
• Pacific island cable hubs connected to U.S. infrastructure recorded elevated concentrations of Chinese fishing vessel activity, particularly around Kiribati, Solomon Islands, and Fiji.
• Extended-duration activity above cable routes was observed across both service and fishing vessel datasets, with more than 2,700 events lasting longer than 24 hours globally during the quarter.

Threat 1: Surveillance & Intelligence Collection Risk

Surveillance-related cable risk is associated with intentional vessel activity conducted in proximity to subsea infrastructure. In this report, activities are defined as vessels maintaining slow speed for more than one hour near known cable routes — a pattern consistent with cable mapping, route surveying, or potential cable surveillance preparation.

Vessel affiliation is a key indicator in assessing elevated risk. While some cable-proximate activity is legitimate, operations involving vessels flagged to, operated by, or affiliated with geopolitical adversaries warrant increased scrutiny, particularly when combined with repeated slow-speed activity, extended presence, or operations near strategic cable corridors. Research and survey vessels, as well as vessels operating under flags of convenience that obscure ownership, are of particular relevance in this context.

This section examines global service vessel activity recorded above submarine cable routes during Q1 2026, highlighting geographic hotspots, flag and affiliation patterns, and notable operational behavior associated with elevated surveillance and intelligence collection risk.

Regional Analysis

Regional analysis in this report is based on strategic cable corridors and maritime operating zones. Because underwater cable systems frequently pass through multiple regions, some cable routes and related vessel activity may be reflected across more than one regional cluster.

Indian Ocean — Highest Risk

Accounts for 63% of all global cable-proximate activity and 87% of all State of Concern (SOC) events. The UAE–Oman corridor is the primary hotspot. Iran’s 62 activities are entirely concentrated here. 

Mediterranean — High Risk

Highest Flag of Convenience (FoC) penetration at 40.6%. Iran accounts for 90% of SoC events (62 of 69). Russia contributes two slow speed activity events near Egyptian infrastructure. China has 4 events with one vessel averaging 25.8 hours — longest average of any Chinese vessel across all regions.

Pacific — Elevated Risk (Extended Presence)

Only 19 SoC events but 20.0% of activities exceed 24 hours — the highest extended-presence rate of any region. China (16 events) and Russia (3 events) are the only SoC actors. 

Atlantic — Moderate Risk

Zero SoC-flagged vessels. FoC accounts for 36.8% (Panama-dominated). Research/Survey vessels are proportionally more common here (7.7% of activity).

U.S.-Connected Cables — Moderate Risk

Zero SoC-flagged activity. Research/Survey vessels at 13.4% — elevated proportion. Hawaii (27 events) and Guam/Northern Marianas (5 events) are significant given their role as Pacific cable hubs linking U.S. military and commercial infrastructure.

Vessel Spotlight: Chinese State-Affiliated Survey Vessel

A Chinese state-affiliated research and survey vessel emerged as the most operationally significant service vessel identified in the Q1 2026 dataset. The vessel conducted four separate slow-speed events in the Arabian Sea during the quarter, totaling 57.3 cumulative hours above strategic cable routes, including activity near the SMW5, FALCON, EIG, and AAE-1 systems. The longest single event lasted 22.3 hours.

The vessel is affiliated with a Chinese state research institution and possesses capabilities relevant to seabed mapping and underwater surveying operations. While survey activity can support legitimate scientific research, the combination of repeated operations, extended dwell times, concentration around major East-West cable corridors, and state affiliation elevates the strategic significance of the activity observed during the quarter.

The Arabian Sea remains one of the world’s most critical cable transit corridors, connecting Europe, the Gulf, South Asia, and East Africa through multiple high-capacity subsea systems. Repeated slow-speed survey activity in this environment warrants continued monitoring as part of broader cable security and infrastructure resilience assessments.

Threat 2: Fishing Vessel Accidental Damage Risk

While surveillance-related cable risk is associated with intentional vessel behavior, the majority of physical damage to subsea cables globally is linked to commercial maritime activity; particularly fishing and bottom trawling operations.

Trawlers operating above subsea cable routes can unintentionally damage infrastructure through the use of heavy seabed gear, including weighted nets, doors, and ground cables capable of snagging, dragging, or severing subsea systems. As global fishing activity intensifies around densely connected maritime corridors, prolonged fishing operations above cable routes remain a persistent infrastructure resilience concern.

This section examines cable-proximate fishing vessel activity recorded during Q1 2026, with a particular focus on trawling activity, extended-duration fishing operations, geographic exposure zones, and regions where commercial fishing activity intersects with critical subsea infrastructure.

Key Findings

• The Indian Ocean recorded the highest concentration of fishing vessel cable-proximate activity globally, driven by dense commercial fishing operations and elevated concentrations of Chinese- and Iranian-linked vessels.
• Trawling-related exposure remained concentrated in the Mediterranean, North Atlantic, and North Sea cable corridors, where prolonged seabed fishing activity intersected major undersea infrastructure routes.
• Chinese-flagged fishing vessels accounted for the overwhelming majority of state-linked fishing activity observed globally during Q1 2026, particularly around Pacific island cable hubs and Indian Ocean corridors.

Trawler-Activity Analysis

Trawlers represent the highest-priority accidental damage risk vessel type. When a trawler’s ground gear — steel cables, chain sweeps, and weighted otter boards — snags a submarine cable, the result can range from minor insulation damage to complete severance. Cable breaks in shallow shelf waters (below 200m) are overwhelmingly attributable to trawling.

UK waters dominate trawler activity with 427 of 1,426 trawler events (30%), followed by Spain (221), France (191), Italy (153), and Denmark (140). Together, these five countries account for 1,132 events, nearly 80% of all recorded trawler activity globally. Their operations are concentrated across the North Atlantic, North Sea, and Mediterranean cable corridors: the densest subsea infrastructure networks in the dataset and the zones where accidental physical damage to cables is most statistically likely.

The geographic concentration of these fleets means that the highest accidental damage risk is generated not by adversarial actors but by allied and NATO-member fishing nations operating in their own traditional grounds. This is not a surveillance or intent concern, it is a persistent infrastructure resilience exposure that increases with fishing season intensity and adverse weather conditions that push trawlers into shallower shelf waters above cable routes.

Regional Analysis

Indian Ocean — Highest Risk (SoC + Trawlers)

Italy (8,835 events) dominates by volume, a figure that reflects Italy’s established distant-water fishing fleet, which has operated in the Indian Ocean for decades, targeting skipjack, yellowfin, and bigeye tuna under Sustainable Fisheries Partnership Agreements. This activity is assessed as low strategic risk. Indonesia (4,830), Sri Lanka (4,270), China (2,114), and Iran (1,790) follow. The Chinese and Iranian concentrations are the operationally significant signal in this region.

Pacific — Highest SoC Concentration

54.4% of Pacific fishing activities are Chinese-flagged (7,138 of 13,122 events). Chinese-flagged vessels are operating around Kiribati, Solomon Islands, and Fiji, all hosting cable landing stations critical to U.S. Pacific communications. Virtually no trawler events (12) — risk profile entirely different from European waters.

Mediterranean — Elevated Risk (SoC + Trawlers)

Dual risk profile: SoC fishing activity (China 385, Iran 294) alongside the primary trawler hotspot. Mediterranean trawlers operate across Spanish, Italian, and North African waters. Qatar (323 events) is a notable presence, likely connected to Gulf fishing operations near cable infrastructure.

Atlantic — Elevated Risk (Trawlers + IUU)

Highest trawler share at 16.7%. French, Spanish, UK, and U.S. trawlers cross some of the world’s most strategically important cable infrastructure — the transatlantic cables. High IUU (261) and Forced Labour (262) counts are the second-highest of any region, driven by Chinese distant-water fleet operations.

U.S.-Connected Cables — Moderate Risk

China-flagged SoC events (68) concentrated in Solomon Islands (23), South East Pacific (14), Kiribati (12), and Fiji (6) — all areas with U.S.-connected cable landing stations. Trawlers (189 events) are primarily French, American, and Irish, operating in North Atlantic zones near U.S.-connected cable routes.

Combined Risk Assessment: Q1 2026

Across both threat categories, Q1 2026 established a consistent geographic hierarchy of cable risk. The Indian Ocean and Mediterranean emerge as the two corridors where surveillance risk and physical damage risk converge — the only regions in this dataset carrying dual exposure across both threat types.

The Indian Ocean is the highest-risk cable corridor by every metric. It accounts for 63% of all service vessel cable-proximate activity, 87% of all State of Concern events under Threat 1, and records the highest concentration of Chinese- and Iranian-flagged fishing vessel activity under Threat 2. The UAE–Oman corridor — where Iran’s entire service vessel SoC footprint is concentrated and where Chinese state-affiliated survey vessels conducted repeated slow-speed operations — remains the single highest-priority geographic focus for cable security monitoring globally.

The Mediterranean presents a different but comparably serious risk profile. It carries the highest Flag of Convenience penetration rate of any region (40.6%), the second-highest SoC concentration under Threat 1 (dominated by Iran at 90% of regional events), and the highest trawling-related physical damage risk of any corridor. The convergence of intentional surveillance-adjacent behavior and dense accidental-damage exposure across the same infrastructure network makes the Mediterranean the region most likely to record a cable-related incident — of either type — in the coming quarters.

The Pacific requires forward attention despite moderate aggregate numbers. China’s 54.4% share of Pacific fishing activity, concentrated specifically around Kiribati, Solomon Islands, and Fiji — all hosting US-connected cable landing stations — represents a deliberate operational pattern rather than incidental presence. The 20% extended-presence rate under Threat 1 reinforces this assessment. The Pacific is the region where the gap between current risk indicators and potential strategic consequence is largest.