Nautilus International identifies three structural gaps: unclear liability when the ashore master loses contact; no safety evidence that one master can oversee multiple vessels simultaneously; and no plan for workforce displacement as bridge officers are replaced by shore-control-room roles.Source: autonomous-land-sea update 4

Why does the MASS Code matter for naval autonomous systems?

The same autonomy technology that runs crewless cargo ships also drives naval minehunters and subsea-cable inspection drones. A regulatory framework normalising shore-based command and control reduces legal risk for navies deploying autonomous systems.Source: event

Does the MASS Code require a human captain on autonomous ships?

Yes. The code keeps a human master legally responsible even when operating from a control room ashore, rather than standing on the bridge of the vessel.Source: International Maritime Organization

Background

The Maritime Autonomous Surface Ships (MASS) Code is the first global regulatory framework governing cargo vessels that sense, navigate and steer with reduced crews or none aboard. The International Maritime Organization adopted it at Maritime Safety Committee session 111 (MSC 111) in London on 22 May 2026 and the Code entered force on 1 July 2026, applying to cargo ships only. It keeps a human master legally responsible even when that master operates from a control room ashore.

Entry into force opens a non-mandatory Experience Building Phase, in which flag states collect operational data and set their own permissions until a binding framework targeted for 1 January 2032. The IMO deferred the detailed Experience Building Phase framework itself, the guidelines governing how that data collection actually runs, to MSC 112 in December 2026, so the Code took effect on 1 July without the operating rules for its own transitional period. Classification societies including DNV and Lloyd's Register already certify autonomous and remotely operated vessels under their own rules, so the code legitimises existing practice rather than leading it. Nautilus International has identified three structural gaps the code leaves unresolved: liability when the master sits ashore and something goes wrong; safety evidence that one master can supervise multiple vessels simultaneously; and workforce displacement as shore-based control rooms replace sea-going officer berths.

The naval significance is direct: the autonomy stack that runs a crewless cargo ship also runs a mine-hunting surface drone or a subsea-cable inspection vehicle. A regulatory framework that normalises shore-based command and control lowers the legal risk for navies fielding uncrewed systems in contested waters.