The IMO MASS Code runway — and what crewless does to condition monitoring.

1. What MASS is

MASS — Maritime Autonomous Surface Ships — is the IMO's term for vessels operating with varying degrees of autonomy, up to and including fully crewless. The IMO classifies degrees of autonomy from crewed-with-automated-support through remotely operated to fully autonomous. DNV's AROS class notations mirror this with four modes: remote control, decision support, supervised autonomy, full autonomy.

2. The regulatory timeline

• May 2026 (MSC 111): the non-mandatory MASS Code is adopted.
• December 2026 (MSC 112): the Experience-Building Phase (EBP) framework is developed.
• 2026–2028: the EBP runs. Operators field autonomous vessels under the non-mandatory code; what they learn feeds the mandatory code.
• 2028: development of the mandatory MASS Code begins.
• 1 July 2030: the mandatory MASS Code is adopted.
• 1 January 2032: it enters into force.

This is the same shape as the IMO biofouling regime (see that primer): voluntary first, mandatory a few years later. The operators and tooling that build the muscle during the voluntary phase are the ones ready when it turns mandatory.

3. The structural change: no crew, no condition loop

Every conventional vessel relies on its crew as condition sensors. The crew walks the deck, descends into ballast tanks, inspects cargo holds, notices the rust streak, hears the wrong sound, files the report. That loop is invisible because it has always been there.

A crewless vessel has none of it. Remove the crew and you remove the entire human condition-monitoring system. The MASS Code and the AROS notations are mostly about navigation, engineering control, and safety systems — but condition assurance is the quieter problem. A vessel that cannot inspect itself, and has no one aboard to inspect it, needs its condition intelligence delivered another way.

4. What the Experience-Building Phase will surface

The EBP (2026–2028) is where operators and regulators learn what autonomous operation actually requires. Condition assurance will be on that list: an autonomous vessel that develops a hull defect, a coating breakdown, a structural crack between port calls has no crew to catch it. Regulators and class societies will want to see how operators close that gap. Structured, machine-readable, audit-traceable condition data is the answer that survives scrutiny.

5. Condition-based survey is converging with autonomy

DNV has stated its direction: use condition monitoring to focus surveys on risk areas rather than running fixed scheduled surveys. For autonomous vessels this is not a nice-to-have — it is the only model that works, because there is no crew to support a traditional survey and remote survey needs structured input. The autonomous-vessel survey regime and the structured-condition-data product are the same need from two directions.

6. Why autonomous electric vessels feel this first

Yara Birkeland — the world's first autonomous electric container ship — is the canonical case. It is crewless (target) and battery-powered. Biofouling increases hull drag; drag drains range. On a crewed diesel ship fouling is a fuel-cost line item. On an autonomous electric ship it is an operational-range constraint that no one is aboard to observe. Condition monitoring moves from compliance task to mission-critical system.

7. What operators should do in the 2026–2028 window

• Specify the condition layer into the vessel, don't retrofit it. Autonomous vessels are being designed and built now. Structured condition intelligence should be a designed-in subsystem.
• Feed the Remote Operations Center structured data. A ROC monitoring a fleet cannot read PDFs. It needs a queryable condition object per vessel — with drift detection across inspections.
• Build the EBP evidence base. What you document during the Experience-Building Phase is what informs the mandatory code. Structured condition data is defensible EBP evidence; narrative PDF is not.
• Treat it as dual-use. Naval USVs face the identical gap. The condition layer that serves a civilian MASS feeder serves a defense USV on the same schema.

8. The Hullproof position

CoatingPassport is the structured condition-intelligence object purpose-built for this. Footage-agnostic ingest (from hull crawlers, ROV, drone, fixed mounts), structured findings with confidence + lineage, drift detection across inspections, agentic-queryable via VQA, and a VLA seam where a finding triggers an autonomous action. It is the condition layer a crewless vessel needs — and it is ready during the voluntary window, not scrambling when the code turns mandatory.