By Alexander Lott, Kristjan Tabri, and Angela Sooba
Introduction
Reportedly, approximately 20,000 seafarers on board some 2,000 ships, including tankers, bulk carriers, cargo ships, and cruise ships, were stranded in the Persian Gulf due to Iran’s closure of the Strait of Hormuz. The United Nations warned that given that the Strait of Hormuz is used for the transport of a fifth of global oil and liquefied natural gas (LNG), as well as a third of fertilizer components, its closure to international navigation would result in a global economic crisis.
Would it be possible for ships to undertake the passage through danger zones, such as the Strait of Hormuz and the Persian Gulf, autonomously via shore-based control centers? Could crew members disembark for the inbound transit and then board the outbound ships in the ports far from the theater of war? Such a method could substantially change the risk calculus affecting commercial shipping and the safety of navigation in dangerous waters.
Potential Use of Unmanned Ships in War Zones for the Protection of Seafarers
Most of the stranded ships fly a neutral flag. In the context of the naval warfare between the United States and Iran, neutral merchant vessels are legally entitled to continue navigating through the Strait of Hormuz under the right of transit passage.
There is a mismatch between what the shipping companies can do legally and what they have decided to do in practice. The seafarers need to return home and international trade needs to resume flowing. Yet the shipping companies have mostly decided to avoid entering the Strait of Hormuz. This is due to the risk of Iran’s attacks on merchant vessels and the danger of striking a naval mine in the suspected Iranian minefield in the international traffic separation scheme (TSS) located in the Omani part of the Strait of Hormuz.
In this context, there is a great danger to seafarers’ right to life. In the shipping companies’ risk-reward calculus, this seems to serve as one of the key factors that deters them from entering the Strait of Hormuz despite the promise of lucrative trade. The insurance companies have confirmed that the shipping companies’ reluctance to transit through the Strait is not due to the insurance companies withdrawing coverage, but rather due to concerns about the safety of the crews. One insurer stated clearly that “The reason ships are not moving is not through a lack of insurance; it is a question of the risk to crew and vessel safety being assessed by the ship masters and owners as too high.”
Convertible unmanned merchant vessels can change this risk calculus and make these transits more favorable. No crew means no hostages or casualties. Removing the crew from the equation also removes the most direct form of political leverage. The vessel, its cargo, and the commercial interests involved would still be at risk – but the immediate threat to human life no longer. The risk that unmanned ships strike a mine or are attacked by Iranian naval or air drones remains. But the fact that such risk does not accompany a threat to life might be worth taking and could still promise profitable trade.
The term “unmanned ship” is used here to cover both remotely controlled vessels and, where communication cannot be guaranteed, vessels with a degree of autonomous capability if communication is lost. How could this method work in practice in the Strait of Hormuz to safeguard human life while enabling the safe transit of trade?
Navigator’s Operational and Technical Perspective
The International Maritime Organization (IMO) has established a Traffic Separation Scheme (TSS) in the Strait of Hormuz – essentially a set of designated traffic corridors that keep inbound and outbound vessel traffic separated. A standard transit route through this sector consists of three legs and two waypoints, both of which fall inside a designated mine danger zone. The total distance of this specific transit is approximately 16 nautical miles (around 30 kilometers). For an unmanned transit, a reduced speed of around 10 knots (roughly 18 km/h) is advisable, giving an estimated transit time of approximately 96 minutes. The slower speed improves shore-based monitoring and reaction time, gives the vessel’s automated systems more opportunity to respond if communication is lost, and reduces the impact should the ship strike a mine.
From a navigator’s perspective, the idea of using remotely controlled and/or autonomous ships for this transit is technically possible. Most modern merchant vessels already have track-control or track-mode capability, meaning the ship can follow a pre-programmed route automatically. A slower speed is not necessarily a problem. In narrow and high-risk waters, it may actually improve monitoring, control, and reaction time.
A weakness to consider is the well-documented GPS-spoofing in the Strait of Hormuz. This phenomenon refers to feeding a vessel’s navigation system with false position data by an external signal. On a crewed vessel, the officer on watch can usually detect it by cross-checking the GPS position against radar, visual observations, the Automatic Identification System (AIS), compass heading, speed, and the planned route. On an unmanned vessel, that human cross-checking function would need to be replaced by redundant positioning systems, automated sensor comparison, and continuous monitoring from shore.
Unmanned ships do not yet have a recognized legal status under the International Regulations for Preventing Collisions at Sea (COLREGs) – the rulebook that regulates how vessels behave around one another at sea. These rules assume there is a human being onboard making decisions and bearing responsibility. An unmanned vessel cannot meet that requirement as the rules currently stand.
In a busy, mixed-traffic environment like the Strait of Hormuz TSS, this creates both legal and practical safety problems. Until COLREGs are updated to address unmanned vessels, fully authorized unmanned transit remains off the table – regardless of what the technology can already do. But the rules are about to change. Indicatively, the IMO adopted the International Code of Safety for Maritime Autonomous Surface Ships (MASS) in May, and the Code will take effect in respect of cargo ships on July 1, 2026.
The use of unmanned ships in danger zones does not make the risk disappear. The mine threat, drone threat, seizure risk, insurance exposure, and political consequences remain. However, the key point is that the current commercial deadlock is caused mainly by the unacceptable risk to human life, not by financial risk. If the crew is removed before the high-risk transit and re-boards after the vessel exits the area, the risk-reward calculation changes significantly.
Can Merchant Ships Be Temporarily Converted for Unmanned Transit?
From a technical perspective, the idea of conducting unmanned merchant vessel transits through the Strait of Hormuz is no longer purely theoretical. The industry already possesses many of the core technologies required for remotely controlled or partially autonomous navigation. The challenge lies less in inventing entirely new ships and more in rapidly adapting existing vessels for temporary unmanned operations in a high-risk conflict environment.
In practical terms, the envisaged unmanned transit would likely rely primarily on remotely controlled operation. It would correspond to the IMO’s definition of a Degree Three MASS, which stands for a remotely controlled vessel operating without seafarers onboard.
However, because communication in wartime conditions can never be guaranteed, the vessel would also require limited autonomous capability corresponding to Degree Four MASS concepts, enabling the ship to continue safe navigation independently if the communication link to shore is interrupted. Three technical components are critical for such operations, including reliable situational awareness, resilient communications, and control over propulsion and steering systems.
Situational Awareness in an Electronic Warfare Environment
Modern merchant vessels already carry extensive navigation sensor suites, including radar, GPS receivers, Global Navigation Satellite System (GNSS) receivers, AIS, gyrocompasses, echo sounders, Electronic Chart Display and Information System, and increasingly camera-based monitoring systems. Together, these systems provide the situational awareness necessary for both remote operation and autonomous navigation.
The challenge is not the lack of sensors, but integrating them into a temporary remote control architecture capable of securely transmitting data to a remote operations center. Rather than deeply modifying existing bridge systems, a more practical crisis-time solution could involve installing standalone modular sensor packages dedicated to unmanned transit operations.
However, the Strait of Hormuz presents a uniquely hostile electromagnetic environment. GPS spoofing and GNSS jamming have already become common in the Persian Gulf region. This means that unmanned vessels cannot rely solely on satellite navigation. Reliable communication between the vessel and the remote operations center is perhaps the single greatest operational challenge in a danger zone. Conventional satellite communications systems remain vulnerable to jamming, cyber interference, and signal degradation during military operations. Potential solutions include multi-layered communication architectures combining satellite links, tactical radios with frequency hopping, line-of-sight systems, and mesh-networked relay communications. Yet no realistic system can guarantee uninterrupted connectivity throughout the transit.
This fundamentally changes the operational concept. The ship cannot depend entirely on continuous steering by humans from shore. Instead, it must be capable of entering a degraded autonomous mode whenever communication is temporarily lost. In practical terms, this could mean the vessel continues following a pre-approved navigation corridor at reduced speed while independently maintaining collision avoidance and route-keeping functions until communication is restored. This concept already resembles the operational logic used in autonomous military systems and unmanned aerial vehicles operating in contested electromagnetic environments.
Future-ready solutions increasingly combine radar mapping, inertial navigation systems, visual navigation, bathymetric matching, and sensor fusion algorithms capable of detecting inconsistencies between navigation inputs. Several commercial maritime autonomy systems are already moving in this direction. Kongsberg, Maritime Robotics, MindChip, Kraken, Sea Machines and several others have all demonstrated remote and autonomous vessel technologies using integrated sensor fusion and shore-based monitoring systems.
Ship Control Integration: The Real Engineering Bottleneck
The most difficult aspect of temporary vessel conversion is likely integration with propulsion and steering systems. Although modern ships increasingly rely on digital control systems using standards (National Marine Electronics Association, Controller Area Network bus architectures, etc.), every vessel possesses unique propulsion layouts, engine automation logic, steering interfaces, and alarm systems. No universal “plug-and-play” autonomous control package currently exists for merchant shipping. Traditionally, adapting autonomous control systems to each vessel individually would require lengthy engineering work, making rapid crisis deployment unrealistic.
This is an area where artificial intelligence and machine learning may significantly reduce the integration burden. One emerging concept is the so-called Self-Adaptive Artificial Captain (SAAC) developed by Estonian deep-tech company MindChip. Rather than manually programming every vessel-specific control logic, the system observes normal crewed operations and learns the relationship between helm commands, propulsion inputs, and the vessel’s physical response. In essence, the ship develops a behavioral model of itself. During ordinary manned voyages before entering the danger zone, the autonomous layer could silently record navigation actions and correlate them with the vessel’s movement, speed changes, turning behavior, and environmental conditions. Over time, the system builds an operational model capable of reproducing the required maneuvers autonomously or under remote supervision. This approach could dramatically shorten the time required to prepare vessels for unmanned transit in danger zones.
Conclusion: Technology is No Longer the Main Obstacle
Significant obstacles remain. Legal uncertainty under COLREGs, cybersecurity risks, insurance liabilities, rules of engagement, and political considerations all remain unresolved. Nevertheless, the core technologies required for temporary unmanned merchant transit already exist in various forms across the commercial maritime, defense, and autonomous systems sectors. The technical and engineering viability of the use of converted unmanned ships in danger zones is possible. The main problem that remains unanswered is whether states, insurers, and shipping companies are prepared to accept a fundamentally different balance between commercial risk and human risk in danger zones.
Alexander Lott is an Associate professor of international law and the law of the sea at the University of Tartu, Estonia and a Research professor (forsker I) at the Norwegian Centre for the Law of the Sea at the UiT – The Arctic University of Norway. He is the author of the books Hybrid Threats and the Law of the Sea: Use of Force and Discriminatory Navigational Restrictions in Straits (Brill, 2022) and The Estonian Straits: Exceptions to the Strait Regime of Innocent or Transit Passage (Brill, 2018), as well as the editor and co-author of the anthology Maritime Security Law in Hybrid Warfare (Brill De Gruyter, 2024). He is co-editor-in-chief of the book series International Straits of the World (Brill, 2026).
Kristjan Tabri is a tenured Professor of Marine Technology at Tallinn University of Technology (TalTech), where his research focuses on the structural response of marine systems subjected to complex loading conditions, including accidental impacts, hydrodynamic loads, and ice–structure interaction. In recent years, he has expanded his research to autonomous surface vessels, intelligent navigation, and self-adaptive control systems for maritime applications. He has authored more than 50 peer-reviewed scientific publications. He is a member of the International Ship and Offshore Structures Congress (ISSC), serves on the board of the Estonian Association of Marine Industries, and is a board member of MEC Engineering Solutions. He is also a founding member and board member of MindChip, a deep-tech company developing intelligent control systems for autonomous vessels.
Angela Sooba is an active seafarer and licensed unlimited Master Mariner with over 20 years of international seafaring experience across a wide range of vessel types and trading areas worldwide, with an additional background as a senior Vessel Traffic Service operator. She has served as Head of Fleet and Head of Maritime Bureau at the Estonian Police and Border Guard Board, overseeing national maritime border security and JRCC Tallinn. She is currently a PhD researcher at Tallinn University of Technology (TalTech), focusing on the modernization of COLREGs for the safe integration of MASS and Dynamic Positioning vessels, combining regulatory analysis with the development and testing of practical engineering solutions.
Featured Image: Arrival of the ship CMA CGM Seine at Port 2000 in Le Havre on its maiden voyage. (Photo via Wikimedia Commons)
Discover more from Center for International Maritime Security
Subscribe to get the latest posts sent to your email.