RATNA

An older hull, stopped, whose last broadcast is itself no longer fresh — a cautious lay-up proxy.

Read from the single most-recent AIS broadcast we hold for this hull — we keep no position history, so this is a point-in-time posture, not a dwell inference. “Likely laid up” is a cautious proxy (an old hull, stopped, with a non-fresh fix), not a confirmed lay-up. Derived in-house from our own AIS feed; weight it by the broadcast age above.

Strong, corroborated adverse evidence — a detention, sanctions exposure or a dark-fleet signal.

A coverage-weighted blend of the 3 components we could read for this hull — the weights renormalise over only the components present, so a thin read is never inflated and a hull is never credited a “safe 0” for a signal it has no row for. Higher means riskier. Derived in-house from government-open port-State-control, flag, sanctions and our own vessel data; weight it by the coverage above.