What Is ECDIS?

ECDIS is a computer-based navigation system that displays official electronic navigational charts (ENCs) together with live data from the ship’s sensors. It is used to plan a passage, then to monitor the ship along that route, and it watches for hazards that a navigator reading a paper chart would have to spot by eye.

An ECDIS has four parts. The chart data is a vector ENC issued by, or on behalf of, a national hydrographic office, which the system converts into its own working format, the system ENC or SENC. The sensors supply position from GNSS, heading from the gyro compass and speed through the water from the log; radar and AIS targets can be overlaid on top. The software handles route planning, route monitoring, chart updates and alarms. The hardware is a computer and a calibrated display, both tested for the bridge environment.

Because the chart is vector data, not a scanned picture, the system knows where the shallow water is. The navigator sets a safety contour and safety depth for the ship’s draught, and the ECDIS raises an alarm if the planned route or the ship’s predicted track crosses it. That anti-grounding check is the main reason ECDIS was made compulsory.

Many chart plotters look like an ECDIS, but only a system that meets the IMO performance standard, has been type approved and uses official charts can count towards the chart carriage rules. The International Maritime Organization calls everything else an electronic chart system, or ECS.

Where no ENC exists for an area, an ECDIS can run in raster chart display system (RCDS) mode with official raster charts. Its alarms then have no depth data to work from, so an appropriate folio of up-to-date paper charts is normally required alongside it.

SOLAS chapter V, regulation 19, made ECDIS compulsory on most ships engaged on international voyages. Carriage was phased in between 2012 and 2018, starting with new passenger ships of 500 gross tonnage and upwards and new tankers of 3,000 gross tonnage and upwards, then working through cargo ships and existing vessels by size. High-speed craft were brought in earlier. Smaller vessels, fishing boats and pleasure craft outside these rules usually run an ECS instead.

Carrying ECDIS also brings two duties for the operator. The first is a back-up arrangement, so that a single failure does not leave the bridge without charts: in practice either a second, independent ECDIS on a separate power supply or a folio of corrected paper charts. The second is training. The STCW Convention requires generic ECDIS training for deck officers, and under the ISM Code the company must also give type-specific familiarisation on the make and model fitted to each ship.

No single document defines ECDIS. Several bodies each own a piece of it.

The hardware matters because the IMO standard sets requirements the screen itself must meet. The chart area used for route monitoring must be at least 270 × 270 mm, which in practice puts most ECDIS screens at around 19 inch and above. Colours must match the S-52 palettes, so displays are calibrated at the factory, and the night palette has to dim far enough to keep the officer of the watch’s night vision. A dimming knob or keys for day, dusk and night modes are common for that reason.

An ECDIS is approved as a complete system, so a display or computer is not type approved for ECDIS on its own. The ECDIS manufacturer specifies and tests the hardware that runs its software, and the hardware is built to pass IEC 60945, including its strict radiated emission limits around the marine VHF band. Our guide to IEC 60945 and maritime computing requirements explains how those tests and DNV type approval fit together.

Our marine monitors include ECDIS versions in several sizes with PCAP touch and day, dusk and night mode keys, and most of the range lists DNV-CG-0339 among its approvals. For planning stations and other bridge computing, our marine panel PCs combine the screen and computer in one panel-mount housing.

We supply marine monitors and computers for bridge consoles as part of a complete system, with the mounting, power input and dimming matched to the console as standard.