How the IMO MASS Code Will Regulate Autonomous and Remotely Operated Cargo Ships

The framework is intended to address the safety, security, and operational challenges created by vessels that rely on advanced digital systems—such as sensors, artificial intelligence, and communications links—to perform navigation and ship functions with limited or no onboard crew.

This international standard is needed because autonomous shipping currently lacks unified regulation, meaning flag states often set their own rules or approval processes for autonomous vessel trials and operations.

Core Safety and Operational Concepts

Although the detailed technical provisions are still being finalized, available documentation shows that the MASS Code will emphasize several core safety principles.

Goal‑based safety framework

Instead of prescribing exact technologies, the code sets high‑level safety objectives and functional requirements that systems must achieve. This approach allows new technologies to evolve while still meeting internationally accepted safety outcomes.

Risk assessment and system design

Autonomous vessels must undergo structured risk assessment and approval processes, evaluating hazards related to autonomy, software, remote control, and system failures. Draft structures for the code include chapters on system design, operational context, and safe‑operation management.

Situational awareness and sensor systems

Autonomous ships rely on integrated sensing systems to perceive their surroundings. Typical architectures combine radar, AIS, lidar, cameras, and sonar, which gather environmental data and feed it into onboard decision‑making systems that manage navigation and collision avoidance.

These systems support continuous situational awareness, enabling the vessel to identify nearby traffic, obstacles, and navigation conditions while operating with minimal human intervention.

Remote operations and autonomy levels

The MASS framework is designed to cover several degrees of autonomy, including:

• Ships with automated systems but crew on board
• Remotely controlled ships with crew on board
• Remotely controlled ships without crew
• Fully autonomous vessels capable of independent decision‑making

These categories reflect the varying roles humans may still play—either onboard or through remote operations centres supervising vessel functions from shore.

Interaction with existing maritime rules

The MASS Code is intended to complement existing IMO instruments rather than replace them. Conventional maritime requirements—including navigation safety principles and conventions such as SOLAS—remain the foundation of regulatory oversight for autonomous vessels.

However, the final text detailing how specific rules—such as COLREGS implementation for autonomous navigation—will be applied has not yet been fully confirmed in the publicly available sources reviewed here.

The Adoption Timeline

The IMO has established a staged rollout designed to test autonomous shipping systems before mandatory regulation takes effect.

2021–2026: Development of the voluntary MASS Code

After the regulatory scoping exercise concluded in 2021, the IMO Maritime Safety Committee began drafting a goal‑based MASS Code.

The current roadmap targets adoption of the non‑mandatory code around 2026, providing an international reference framework for early deployments of autonomous cargo ships.

2026–2030: Experience‑building phase

Following adoption of the voluntary code, an experience‑building phase will allow shipping companies, technology developers, and regulators to test autonomous systems within the structured framework.

Insights from this phase are expected to inform refinements to the final mandatory code and related amendments to existing maritime conventions.

2030–2032: Mandatory implementation under SOLAS

The long‑term objective is to incorporate the MASS Code into the SOLAS Convention, making it legally binding for applicable ships. The current regulatory roadmap anticipates mandatory entry into force around 2032, following the normal amendment cycle of SOLAS.

Why the MASS Code Matters

Autonomous shipping promises operational efficiency, new logistics models, and potentially improved safety through advanced sensing and automation. But without international rules, large‑scale deployment would face legal uncertainty and inconsistent standards.

The MASS Code represents the maritime sector’s attempt to solve that challenge by creating a global regulatory architecture for autonomous vessels—one that allows innovation while maintaining the same fundamental safety expectations applied to conventional ships.

If the roadmap proceeds as planned, the period between 2026 and 2032 will serve as the maritime industry’s transition window from experimental autonomous shipping toward a fully regulated global operating environment.