The silent war for the Atlantic is moving from the depths of the ocean to the skies above it. For years, the Portuguese Navy has played a cautious game of cat-and-mouse with Russian vessels traversing the nation’s vast maritime jurisdiction, but recent disclosures suggest a tactical escalation that transcends mere transit.
New data reveals that the Portuguese Navy has detected the deployment of drones launched from Russian ships operating within Portuguese waters. While the military has largely kept these encounters under wraps, the revelation underscores a growing trend of “gray zone” warfare—activities that fall below the threshold of open conflict but are designed to test defenses, gather intelligence and signal geopolitical resolve.
This shift in activity comes amid a surge in the presence of the so-called “ghost fleet”—a clandestine network of aging tankers used by the Russian Federation to bypass international sanctions on oil exports. These vessels, often operating with disabled or spoofed Automatic Identification Systems (AIS), have turned the Atlantic into a corridor for sanctions evasion and, increasingly, for strategic reconnaissance.
The Logistics of a ‘Ghost Fleet’
In my years reporting from conflict zones and diplomatic hubs across 30 countries, I have seen how the tools of commerce are frequently weaponized for intelligence. The “ghost fleet” is a prime example. By utilizing ships with opaque ownership and substandard insurance, Moscow can move vast quantities of crude oil while remaining invisible to traditional maritime tracking.
However, invisibility is a double-edged sword. To avoid detection by Western satellites and naval patrols, these ships often engage in “dark” maneuvers. According to statistics released by the Portuguese military in January, the scale of this activity is significant. In 2025 alone, 69 Russian vessels passed through waters under Portuguese sovereignty or jurisdiction.
The Portuguese Navy did not simply watch these ships pass. The military conducted 373 separate monitoring actions to track the fleet’s movements, indicating a high state of alert and a recognition that these vessels may be carrying more than just oil. The use of drones—unmanned aerial vehicles (UAVs)—represents a qualitative jump in the nature of these incursions.
| Metric | Confirmed Data |
|---|---|
| Russian Vessels Detected | 69 |
| Navy Monitoring Actions | 373 |
| Primary Tactic | “Ghost Fleet” / AIS Spoofing |
| New Capability Detected | Ship-launched UAVs (Drones) |
From Transit to Surveillance
The detection of drones marks a transition from passive transit to active Intelligence, Surveillance, and Reconnaissance (ISR). When a ship simply sails through a corridor, it is a matter of navigation; when it launches a drone, it is a matter of espionage.
The sensitivity of this information was highlighted during a visit to the Base Naval do Alfeite on December 30, 2025. During a briefing with António José Seguro, then a presidential candidate, high-ranking Navy officials disclosed the drone activity—information that had previously been held under strict reserve. The choice of location for this disclosure is telling; Alfeite is a critical hub for Portuguese naval operations and a symbol of the nation’s Atlantic commitment.
Military analysts suggest that these drones are likely being used to:
- Map Coastal Defenses: Identifying gaps in Portuguese and NATO radar coverage along the Atlantic coast.
- Monitor Undersea Infrastructure: Tracking the locations of critical fiber-optic cables that link Europe to the Americas.
- Test Response Times: Measuring how quickly the Portuguese Navy and its allies react to an unidentified aerial presence.
The Strategic Stakes of the Atlantic Flank
Portugal occupies a pivotal position in the NATO alliance, guarding one of the most critical maritime flanks in the world. The Portuguese Exclusive Economic Zone (EEZ) is one of the largest in the globe, making it a primary area of interest for any power seeking to project influence in the Atlantic.
“The Atlantic is no longer a sanctuary of peace, but a theater of competition,” notes one maritime security expert. “When Russia deploys drones from tankers, they are telling NATO that no part of the ocean is off-limits.”
The “ghost fleet” provides the perfect cover for this activity. Because these ships are technically commercial vessels, the Russian government can maintain a level of plausible deniability. If a drone is detected, Moscow can claim it was a private security measure or a technical malfunction, avoiding the diplomatic fallout that would accompany the deployment of a formal spy ship.
What Remains Unknown
Despite the Navy’s monitoring efforts, several critical questions remain unanswered. The Portuguese military has not publicly specified the type of drones detected—whether they were little, commercial-grade quadcopters or more sophisticated, long-range military UAVs. It remains unclear if these drones were targeting specific military installations or conducting general environmental mapping as a cover for intelligence gathering.
There is also the question of the “ghost fleet’s” ultimate destination. While many of these ships are bound for Asian markets, their frequent detours into Portuguese waters suggest that the transit is not merely about the shortest route, but about the strategic value of the detour itself.
Looking Ahead
The escalation of Russian maritime activity is expected to prompt a review of Atlantic surveillance protocols within NATO. As the “ghost fleet” continues to evolve, the reliance on traditional radar is proving insufficient, necessitating a greater investment in satellite-based synthetic aperture radar (SAR) and AI-driven anomaly detection to spot “dark” ships before they launch their payloads.
The next critical checkpoint will be the upcoming NATO maritime security summit, where Portugal is expected to present its findings on “gray zone” incursions. This report will likely influence the allocation of resources for Atlantic patrol aircraft and the deployment of additional unmanned underwater vehicles (UUVs) to protect the seabed.
We invite our readers to share their perspectives on the balance between maritime sovereignty and international diplomacy in the comments below.
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