MASS Code

The Maritime Autonomous Surface Ships (MASS) Code is the first worldwide rulebook for cargo vessels that navigate and steer with a reduced crew or none aboard. The International Maritime Organization adopted it at Maritime Safety Committee session 111 in London on 22 May 2026 and set a mandatory compliance date of 1 January 2032, with the years before that forming a voluntary Experience Building Phase in which individual flag states decide what to permit.

Beyond shipping, the Code carries an indirect naval dividend: the shore-based command-and-control software that steers a crewless cargo ship is close kin to the software steering a mine-hunting surface drone or a subsea-cable inspection vehicle, so a framework that normalises remote command lowers the legal risk for any navy fielding uncrewed vessels in contested waters. Classification societies including Lloyd's Register and DNV already certified autonomous ships under their own rules before the Code existed, which is why its practical effect has been to catch up with industry practice rather than set the pace.

For operators, the Code's chief limitation is what it Left unwritten: the Experience Building Phase that should govern the transition years was not itself defined at entry into force, deferred instead to the Committee's December 2026 sitting. Seafarers' representatives argue the six-year voluntary window lets operators run ahead of enforcement before the 2032 deadline bites.