IMO’s autonomous-ship safety code is now operational, with master accountability retained

The International Maritime Organization’s International Code of Safety for Maritime Autonomous Surface Ships (MASS Code) entered into effect on 1 July 2026. Adopted by the Maritime Safety Committee in May under resolution MSC.595(111), it is the first global framework specifically addressing the design, construction, operation and certification of autonomous and remotely controlled commercial ships.

The Code is non-mandatory at this stage. It applies to cargo ships within SOLAS Chapter I—generally ships of 500 GT and above engaged on international voyages—and IMO recommends that administrations apply it, as far as practicable, to smaller MASS as well. Its immediate purpose is to support consistent trials and early commercial deployment while states and industry build operational experience for a future mandatory SOLAS regime.

Verified requirements are deliberately goal-based rather than technology-prescriptive. Operators must define each intended operating mode, identify operating limits—including weather, visibility, sea state, water depth and time-of-day constraints—and specify what the vessel will do if conditions move outside those limits. Risk assessment and lifecycle risk management are central. The Code also addresses navigation, connectivity, remote operations, fire safety, search and rescue, system robustness and cybersecurity.

A key allocation of responsibility is already clear: the master retains overall responsibility for the ship at all times, including where the master is ashore. Remote Operations Centres must be assessed, certified and operated within a robust Safety Management System. This means autonomous capability does not remove the need for a defensible command structure, clear intervention authority, competence controls, records and emergency arrangements.

For shipowners, managers, charterers and P&I interests, the practical issue is not whether a vessel is described commercially as “smart”. A ship qualifies as MASS only where autonomous or remote technology replaces or supports functions normally performed by onboard personnel and it has completed the applicable approval process and holds a valid MASS Safety Certificate. Conventional vessels with enhanced automation receive no special regulatory status or exemption.

Why this matters: the Code provides a common baseline for technology due diligence, charter-party operational planning, insurer questionnaires and port-interface discussions before binding rules arrive. Operators considering remote-navigation, machinery, cargo or bridge functions should map each function against the approved operating mode, SMS procedures, communications resilience, cyber controls and the master’s retained authority. IMO’s roadmap envisages an Experience-Building Phase framework at MSC 112 in December 2026, development of a mandatory Code in 2028, and expected adoption by 1 July 2030 for entry into force on 1 January 2032.