Autonomous and Remotely controlled vessels (Law issues, maintainability, Reliability, Safety and Security)


Autonomous navigation systems can have the ability to communicate with similar systems using ship to ship information and communication technologies. System-based decision-making processes could be programmed based on a predefined set of rules so that these highly autonomous systems could participate in the traffic that abide strictly by rules and standard information transfer.

These systems may not be able to communicate with human operators in the same way as other similar systems, and cannot predict the human behaviors on the same basis as autonomous systems. The autonomous navigation system may only be able to respond with predetermined decision criteria and logical sequence whereas a human operator can improvise.

 That will typically form their expectations regarding the approaching ship behaviors according to their own observations of the status and information provided by various equipment and sensors of the encountering vessels. The communication between autonomous systems and human operators would be indirect in nature. For manned ship to form expectations about the behavior of the remotely controlled or fully autonomous vessels, interpreting the information transmitted from the approaching vessels would be essential.

In the case of remotely controlled vessels under D2 and D3 operations, it is the vessel that is responsible for safe navigation and decision-making, not the remote-control operators that submitted the request. Various unpredictable motions relate to vessel status and maneuvering behavior can also be expected for vessels at sea due to ocean wind, wave, and current conditions. 

Any of the information channel or sensory failure would become a source of error propagation and could influence the accuracy of the decisions made by future vessels. This means, the communication and information exchange mechanisms between systems and humans would require more functionalities as well as the safety and security assurance in both manned and unmanned MASSs. 

Previous studies have noted that the adoption of a higher degree of automation could bring benefits but also creates new error pathways and brings an additional set of safety challenges to the navigation system in shipping (Lützhöft and Dekker 2002; Porathe et al. 2018). 

Based on the observation of the risk analysis, the safety issues related to collision avoidance, cyberattacks, autonomous navigation system failure, and malfunction are more likely to happen with severe consequences for the ships with higher degree of autonomy. 

Human-related safety issues such as occupational injuries, man overboard, and human health issues onboard of ships will be reduced due to a higher degree of autonomy with the respective consequences being eliminated. Unpredicted behavior of approaching vessels would be a safety challenge for all vessels with severe consequences.

Nevertheless, the likelihood to avoid this challenge is higher by onboard human operators in comparison to autonomous navigation systems, due to the lack of observations and information sharing and interpretation.

Realizing mixed maritime traffic conditions would be a fundamental requirement for achieving autonomy at sea. Autonomous vessels at D3 and D4 have to corporate with other manned vessels under complex scenarios. 

Insufficient communication and information exchange could potentially increase the likelihood of failures in agreement seeking, status understanding, and intent sharing in close ship encounter situations. 

MASS at D3 and D4 must provide highly intelligent system capabilities to be able to perceive, understand, and predict its own ship status as well as understand approaching vessel’s behaviors and respond in time commensurate with the activities in its environments. 

Their safety assurance must also address the non-deterministic behavior of these systems and vulnerabilities arising due to potential divergence of situation awareness between human operators and autonomous navigation systems.

Future research opportunities

This study leads to several future research avenues.

Firstly, cooperative navigation between conventional vessels, manned or unmanned remotely controlled and fully autonomous vessels is a new research topic in the field of intelligent transportation systems, i.e., same applies to the automobile industry. 

Future research can explore how a MASS at D3 and D4 should cooperate with conventional ships and how to optimize decision-makings in mixed navigational situations.

The projected complexity increase is associated with the future autonomous ship navigation systems; it is therefore likely that additional communication methods and safety assurance methods and technologies will be required.

 A sufficient and secured communication and information exchange approach is projected to be essential for increasing the availability of ship autonomy.

Secondly, a comprehensive safety analysis requires a thorough understanding regarding all sources of hazards involved in both system development and operations. The human–machine interactions would mean that the hazard profile could be different in comparison to the hazards recognized from the traditional ship system design and operations. 

Considering the scope of the hazard analysis, a more systemic thinking approach would be suited in order to obtain a thorough understanding regarding the sources of hazards. 

In this regard, the Systems Theoretic Process Analysis (STPA) method (Leveson 2011), a hazard analytic technique from System-Theoretic Accident Model and Processes (STAMP) model, would be particularly suited for this hazard analysis purpose.In additional to the technical aspects, it would also be interesting to explore the MASS adoption issues from human, economic, and wider societal perspectives. 

Against the backdrop of a persistently weak global economy and challenging trade landscape, the outbreak of the COVID-19 pandemic has further affected maritime trade at an unprecedented scale and speed, and shone light on the vulnerabilities of the maritime transportation networks (UNCTAD 2020). 

Despite the downside of the pandemic, it has also led to an acceleration in automation and digital transformation of the shipping industry that has been underway for decades. 

Many maritime stakeholders, e.g., shipping companies, customs officials, port authorities, and freight forwarders, have adopted automated solutions and digital business models to maintain operations and reduce the manpower and operating expenses.

 Physical paper-based transactions and human to human contacts have now been digitalized or automated; electronic freight trading and online freight forwarding—which have been around for some time—are now integrated to a greater extend.

 Future research can also explore how the COVID-19 pandemic would amplifying the opportunities and challenges from the digital transformation to further facilitate the industry in developing remotely controlled and autonomous ships to be operated in the post pandemic period.


The move towards greater autonomy at sea would be a natural evolution of the maritime transportation.

 To effectively leverage the advantages of the emerging automation technology and to unlock the long-term values of these new types of ships for the maritime industry, the forward path must be guided by extensive research collaborations and explorations to address the safety, legal, economic, and security challenges of MASS. 

One of the major issues to be considered is the safety issues related to MASS operation in a mixed navigational environment where conventionally manned, remotely controlled, and unmanned vessels are interacting at the same sea areas.

 The safety challenges highlighted in this paper hopefully shed light on further thoughts and research discussions for improving the design of future autonomous navigation systems.