ECDIS

ECDIS is a navigation information system that displays electronic chart data, integrated with position fixing (GPS/GNSS), and other navigational data. A compliant ECDIS can be used in lieu of paper charts if it meets IMO performance standards and uses the correct chart type.

• Route must be checked at appropriate scale for each phase — do not plan a coastal approach on a small-scale overview chart
• Safety contour and safety depth must be set before loading the route
• All waypoints must be checked visually on the chart — ECDIS route planning can produce straight lines through shallow water if waypoints are not carefully placed
• Route check function must be run — the system will flag any hazards along the planned track
• No-go areas must be identified and wheel-over positions confirmed
• Plan must be checked and approved by the Master before departure
• ENCs must be up to date — check update status before sailing

After the route is laid, the automated route check interrogates every leg's corridor against the safety contour and charted danger objects. The discipline is in the handling: every warning individually examined and resolved — most are seconds each, but the isolated wreck inside your XTD looks identical to the trivia until it is read. Clicking through warnings wholesale is the signature behaviour in ECDIS-assisted groundings. Two display disciplines to pair with it: review the route at compilation scale (over-zoomed-out, SCAMIN suppresses symbols and isolated dangers can simply not display), and check the update status of every cell on the route — ENCs are corrected by weekly digital updates, applied and logged, and the ECDIS can show each cell's currency, which is exactly what a Port State inspector asks it to do.

The displayed ship position is the GNSS feed: every jamming, spoofing and datum problem arrives on the ECDIS screen wearing the chart's authority, with the AIS and autopilot agreeing because they drink from the same source. The defence is the same independence doctrine as the chartwork module: radar overlay or ranges compared against the charted land, visual bearings, the echo sounder against expected depths — and the instinct that when the radar picture and the ECDIS disagree, you slow down and believe neither until resolved. The MAIB's ECDIS grounding pattern is stable across reports: safety values wrong or defaulted, route check warnings dismissed, over-zoom hiding the danger, alarms silenced as noise, and a bridge team watching the screen instead of the water. Every element is procedural — which means every element is preventable by the OOW who treats ECDIS as a powerful instrument to be configured, not an authority to be obeyed.