At its 111th session in London (13–22 May 2026), the IMO Maritime Safety Committee adopted the International Code for the Safety of Maritime Autonomous Surface Ships (MASS Code). This is the first global framework for ships that operate with reduced or no crew on board. It is a milestone for regulators, shipowners and maritime training institutions alike.

A non-mandatory code first

The Code is non-mandatory and took effect on 1 July 2026. This allows Member States and industry to apply and test it before it becomes binding. The IMO’s planned route to a mandatory regime is:

MSC 112 (December 2026): a MASS Working Group is re-established to develop an experience-building phase framework.
2028: work on a mandatory Code begins, drawing on the non-mandatory Code and experience gained, including a possible new SOLAS chapter.
By 1 July 2030: expected adoption of the mandatory MASS Code.
1 January 2032: expected entry into force.

What the Code covers

The MASS Code applies to cargo ships within the scope of SOLAS Chapter I. It is goal-based, and its requirements cover:

Navigation, connectivity and remote operations, including the integration of Remote Operations Centres (ROCs)
Fire safety and search and rescue
Risk assessment, robust system design and cybersecurity
Continued compliance with SOLAS and other mandatory IMO instruments

One principle stands out. The master remains responsible for the ship at all times, even when not on board. Human accountability does not disappear with autonomy; it moves to new roles and locations.

What this means in practice

For maritime administrations: flag and port States will need procedures to assess, approve and monitor autonomous operations under a non-mandatory code. That includes how ROCs and remote operators are recognised and audited.

For ship operators: any autonomy project now has a recognised reference framework. Risk assessments, cyber-resilience and ROC arrangements should be documented against the Code from the start.

For MET institutions: remote operation, supervision of automated systems and cyber awareness are becoming core competences. Curricula and simulator scenarios should start reflecting this ahead of the ongoing STCW review.

How Polaris can help

Polaris Marine Survey and Consultation supports administrations and operators with regulatory gap analysis, risk-assessment review and the development of procedures and training aligned with new IMO instruments. Contact us to discuss how the MASS Code affects your organization.

Sources: IMO press briefing on the MASS Code; Lloyd’s Register MSC 111 summary; MSC 111 key outcomes.