Maritime Insights

ECDIS Safety Parameters

Most ECDIS-assisted groundings share an uncomfortable feature: the equipment worked exactly as configured. The alarm did not sound because the safety contour was set to a value that made the hazard invisible, or because the check scale was wrong, or because the officer had muted the look-ahead alarm after hundreds of nuisance activations in confined water. ECDIS does not run ships aground; parameters chosen by people do. Accident investigation reports — the Ovit grounding on the Varne Bank among the better-known — repeatedly find safety settings that were never adjusted from defaults, never understood, or set once at handover and inherited blindly by every subsequent watchkeeper. This article explains the parameters that actually control what the ECDIS warns you about: the safety contour and how it differs from safety depth, the shallow and deep contours that frame the picture, and the cross-track distance and look-ahead settings that define the safety frame around your planned route. It covers the alarm fatigue problem honestly — an ECDIS that cries wolf on every leg teaches watchkeepers to silence it, and the fix is better settings and better route checking. It lists the setup errors found in audits: default values never changed, safety contour shallower than the ship's draft logic requires, unchecked route legs, and scale mismatches between planning and monitoring views. Written for second officers who plan routes and senior officers who verify them, this is the configuration conversation your bridge team needs before the next pilotage, not after the next investigation.