By Joanne Waters
|Published 14 May 2026
2026 will be a landmark year for the regulation of autonomous transport technology. The UN is scheduled to adopt a global technical regulation for autonomous driving systems in June and in May the IMO is expected to adopt the Voluntary MASS Code (the "Code") for autonomous ships.
In this article we look at the application of the Code, what it means for stakeholders, and the legal issues to consider as you prepare for its implementation.
The IMO began its work on regulating maritime autonomous surface ships in 2017 with a regulatory scoping exercise aimed at understanding how current IMO instruments might apply to such ships. After the identification of several gaps and obstacles in existing IMO instruments, work began on developing a goal-based regulation and this was largely completed towards the end of 2025. The final draft of the Code has now been submitted to the MSC for approval at MSC 111 later this month.
The Code is intended to be technologically neutral and aims to encourage innovation whilst continuing to ensure to ensure "safe, secure, and environmentally sound ship operations".
The current iteration of the Code is voluntary only. However, given the enthusiastic participation of leading maritime states in the development of the Code, we expect that several will adopt the Code into domestic law.
Following adoption, there will be an "experience building phase" ("EBP") designed to allow for review and improvement of the Code, informed by the practical experience gained during this phase. Several important issues that have been left out of the current version of the Code are expected to be addressed during the EBP, including:
However, the purpose of the EBP, its scope, and the form and mechanism of providing feedback, are yet to be decided. Following the EBP and the review and amendments to the Code, the current roadmap is for a Mandatory MASS Code to enter into force in January 2032.
Whilst the Code is not yet in final form, the draft wording provides for its application to "cargo ships to which SOLAS chapter I applies, including any associated Remote Operations Centre(s) (ROC(s)), which have systems and functions that enable autonomous or remote operations, when the Administration deems that compliance with other applied instruments is impracticable or insufficient". It is therefore intended to work alongside existing IMO regulations, adding a layer of complexity to the compliance framework.
"Autonomous" is defined as "processes or equipment in a system which are designed and verified to, under certain conditions, be controlled by automation, without human assistance". This definition is capable of applying to a wide range of systems, meaning the Code potentially applies not only to highly-automated, unmanned vessels of the kind we are yet to see commercially available, but also to vessels which are largely conventional and fully manned, but may have a single autonomous system installed which is capable of performing a key function that would otherwise be performed by the crew. With the speed of technological developments meaning that autonomous systems are now commercially available for key functions such as autonomous navigation and autonomous mooring, one can reasonably expect more vessels to be equipped with such systems in the near future, thereby meeting the relatively low bar for the application of the Code.
The Code introduces entirely new concepts, documents and certification processes that Flag States, Port States, insurers, developers, designers, yards and owners will need to become familiar with.
For example, to obtain approval and certification, the MASS as a whole must have a defined "operational envelope", which includes the "operational design domains" of each individual autonomous system installed. There must also be an overarching "concept of operations" document which describes the technical characteristics of the proposed system, including any limitations, sets out the procedures and criteria for changing from one mode of operation to another, describes how humans are involved, and addresses any remote operating centre that supports the Vessel. This is a key document in the approval and certification process, as well during the operational life of the Vessel.
The preparation of these important documents will require close collaboration between stakeholders, from the design stage and throughout the Vessel's or system's operational life. Decisions will need to be taken and documented as to who will be responsible for preparing these documents and keeping them updated throughout the Vessel's lifecycle, and who will be in turn be responsible for any errors in those documents.
The underlying rationale for the certification and operational concepts set out in the Code appears to be that autonomous systems and MASS are a "system of systems", which will be approved for use in a particular geographic area, in particular traffic conditions, and in particular environmental conditions. This is fundamentally different to the current processes that apply to the design, certification and operation of a conventional vessel, which would typically face no limitations on the permissible operational context, save for draft and ice restrictions.
This narrower approach to certifying and operating MASS reflects the nascent state of the underlying technologies, uncertainties regarding consistent safety performance across all sea states and in all traffic conditions, and caution around the complex interactions between humans and machines. It also raises several questions: what happens if the permitted operational context is changed, or inadvertently breached? Who pays for any re-certification that may be required as the operational capabilities of the system evolve, and what happens whilst the system is waiting to be re-certified? Will Owners need to ensure the trading limits in their time charters are updated to reflect the operational and safety limits of any installed autonomous systems, and to give them the right to refuse any orders that go beyond those limits? If a MASS is involved in a collision whilst operating outside of its permitted limits and context, what impact does that have on the Vessel's insurance and on the Owners' culpability to third parties? Is a MASS operated outside of its permitted operational limits seaworthy? These questions are not addressed by the Code and will therefore need to be worked out between parties on a case-by-case basis.
The draft Code also does not address issues regarding liability for losses caused by the failure or malfunction of autonomous systems or MASS. For autonomous systems which are powered by AI, which is likely to be most if not all maritime applications, there is currently no other international regime that governs liability. The question of liability for harms caused by AI is generally unsettled across all jurisdictions and all industries. Consequently, there is little to no case law to draw on to make an informed judgment as to how such liability is likely going to be apportioned. Developers and buyers of such systems will therefore need to carefully address the allocation of liability via contractual means by reference to their own risk tolerance.
The introduction of autonomous systems onboard otherwise conventional, manned vessels, raises significant operational and legal questions around responsibility. Autonomous systems which can operate in multiple modes, which require varying degrees of human oversight or intervention, are particularly concerning as their use will require clear instructions to be provided to the crew on when and how they should intervene. It is not difficult to imagine errors being made, particularly during high pressure manoeuvres or near-miss scenarios, opening up questions around crew competence, seaworthiness and the implementation of proper systems for the sound management of the human-machine interface. Notably, the draft Code mandates that there should be a "human master responsible for a MASS, regardless of the mode of operation, and the master should have the means to intervene when necessary". This indicates that at least for now, the status quo will remain that the Master, and in turn Owners, will be primarily liable for losses arising from the use of automated or AI-driven systems, and will need to seek recourse against developers and system vendors for losses that also constitute a breach of the contract with the developer or supplier of that system.
The Code also introduces and regulates remote operating centres and remote operators, bringing entirely new parties into the regulatory regime and raising questions around their accountability and ability to respond to a claim in circumstances where they are not yet required to hold mandatory insurance. The complex interactions between the jurisdictions of the Flag State and host state for remote operating centres that are based outside of the Flag State are yet to be worked out and are likely to be dealt with on an ad hoc basis at least during the early stages of implementation.
The Voluntary MASS Code is not business as usual, but a marked departure from the familiar processes that govern the design, build, purchase and operation of conventional vessels.
If you are an Owner looking to install an autonomous system on a vessel, your compliance scoping is now going to need to include a review of the Code, and your due diligence procedures for the assessment and selection of suppliers of autonomous systems is going to need to be updated to reflect the Code's detailed requirements.
If you are a developer looking to influence the forthcoming mandatory MASS Code, it would be a good time to seek to enter into partner or pilot projects with shipowners from the Flag States who have adopted the Code voluntarily, as it is these Flag states who are likely going to be the most influential voices in the experience building phase. Early and frequent conversations with the relevant Flag States regarding certification are also likely to be useful.
If you are developing, buying, operating or investing in MASS and would like to learn more about the impact of the Code, please join our webinar on 18 June by signing up here.
If you are developing autonomous systems or looking to add autonomous systems to your fleet, DACB's dedicated Maritime Technology team would be happy to share with you how we are helping clients navigate the new risks arising from these systems, to ensure they are deployed safely and with full internal and external compliance. Please contact Joanne or your usual DAC Beachcroft contact for more information.
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