IMO adopts MASS Code for autonomous and remotely operated ships

The International Maritime Organization (IMO) has adopted a new International Code of Safety for Maritime Autonomous Surface Ships (MASS Code), establishing a regulatory framework for the operation of autonomous and remotely controlled commercial vessels.

The Code was approved during the 111th session of the Maritime Safety Committee (MSC 111) held in London from 13 to 22 May and is intended to support the safe integration of AI-enabled and remotely operated ships into international shipping.

Framework for autonomous shipping

The MASS Code introduces goal-based requirements covering the design, approval and operation of autonomous and remotely controlled cargo ships. It addresses areas including navigation, connectivity, cybersecurity, fire safety, remote operations and search and rescue procedures.

Under the framework, autonomous ships will still be required to comply with the International Convention for the Safety of Life at Sea (SOLAS) and other mandatory IMO instruments.

The Code will enter into effect as a non-mandatory instrument from 1 July 2026, allowing IMO Member States to gain operational experience before the development of a mandatory version under SOLAS.

IMO Secretary-General Arsenio Dominguez said:

“This landmark achievement positions IMO at the forefront of regulating emerging technologies, demonstrating the Organization’s ability to anticipate and shape the future of shipping. It represents a major step forward, enabling innovation while ensuring that safety, accountability and the human element remain at the core of maritime operations.”

Human oversight remains central

The IMO defines an autonomous ship as a vessel using onboard technology capable of controlling actions without human intervention.

While fully autonomous or crewless commercial ships remain limited, the number of international trials involving remote and autonomous vessel operations has increased in recent years.

The new MASS Code places strong emphasis on human oversight, including maintaining the responsibility of the ship’s master at all times, even when the vessel is operated remotely through Remote Operations Centres (ROCs).

The framework also incorporates risk assessment procedures, cybersecurity safeguards and system reliability requirements aimed at ensuring safety levels equivalent to those of conventional vessels.

Roadmap toward mandatory rules

The MASS Code is the result of nearly a decade of technical discussions, legal work and vessel trials involving IMO member states and industry stakeholders.

The IMO outlined the following roadmap for future development:

• December 2026: MSC 112 to establish an Experience-Building Phase (EBP) framework
• 2028: Development of a mandatory MASS Code and associated SOLAS amendments
• By 1 July 2030: Expected adoption of the mandatory MASS Code
• 1 January 2032: Anticipated entry into force of mandatory regulations

Additional MSC 111 decisions

In addition to adopting the MASS Code, the Maritime Safety Committee also approved several other measures linked to maritime safety and decarbonisation.

Interim ammonia fuel safety guidelines

The committee approved interim guidelines for ships using ammonia cargo as fuel, supporting the safe design, construction and operation of ammonia-fuelled vessels.

It also approved interim training guidelines for seafarers working on ships using:

• Methyl and ethyl alcohol fuels
• Ammonia fuels

The committee further clarified how the “one ship, one code” principle applies to gas carriers operating on alternative fuels under the IGF and IGC Codes.

LRIT ship tracking amendments

MSC 111 approved amendments to the SOLAS Convention aimed at improving access to Long-Range Identification and Tracking (LRIT) data.

The changes would allow coastal states to access standard ship position reports free of charge, supporting maritime safety, environmental monitoring and search and rescue operations.

VDES adoption for ship communications

The committee also adopted a resolution introducing the VHF Data Exchange System (VDES) into the IMO framework as an enhanced alternative to the current Automatic Identification System (AIS). VDES is intended to provide more secure and higher-capacity ship communication and tracking capabilities, including authentication features designed to reduce spoofing risks. The regulations are expected to enter into force on 1 January 2028.