The International Maritime Organization (IMO) has adopted a new International Code of Safety for Maritime Autonomous Surface Ships (MASS Code) at the 111th session of the Maritime Safety Committee in London.

The MASS Code aims to support the safe integration of autonomous and remotely operated commercial ships into global shipping. It sets out a comprehensive, goal-based framework to ensure that autonomous vessels are built, operated and certified at equivalent safety and environmental standards to conventional ships.

The Code applies to large internationally-trading cargo ships and will take effect from 1 July 2026. It will start on a voluntary basis for at least two years, giving Member States the opportunity to test its use while paving the way for making it mandatory under the SOLAS Convention.

A Maritime Autonomous Surface Ship (MASS) is a ship capable of operating with varying levels of independence from human interaction. This ranges from automation with crew on board, to remotely-controlled vessels with or without crew, to fully autonomous vessels able to make decisions independently.