Chartplotter

A chartplotter is a device used in marine navigation that integrates GPS data with an electronic navigational chart (ENC).

The chartplotter displays the ENC along with the position, heading and speed of the ship, and may display additional information from radar, automatic identification systems (AIS), or other sensors.

As appropriate to particular marine applications, chartplotters may also display data from other sensors, such as echolocators or sonar.

Electronic chartplotters are by nature CPU- and GPU-intensive applications. Chartplotters need to retrieve the navigation signal (Galileo, GPS, GLONASS, WAAS, etc.) and overlay that on a map. Map updates on dedicated hardware typically have screen refresh rates from 5 Hz to 30 Hz.

Some navigation software can run on standard computers (and mobile phones, etc.) but most higher end systems are dedicated hardware. Especially when the chartplotter generates three-dimensional displays, as used for fishing, considerable processing power and video memory may be required.

As with all marine systems, chart-plotters generally are not used alone. In commercial ships, they are integrated into a full system of marine instruments that can guide the ship under any conditions. These other instruments include sonar transducers, integration with two-way radio communication devices and emergency locators (EPIRB).

The integration of these devices is very important as it becomes quite distracting to look at several different screens. Therefore, displays can often overlay charting, radar, sonar into a single system. This gives the captain unprecedented instrumentation to maneuver the ship. With digital backbones, these devices have advanced greatly in the last years. For example, the newer ones have 3D displays that allow you to see above, below and all around the ship, including overlays of satellite imaging.

An individual electronic chart, or, more commonly, a database of charts, is the heart of a chartplotter. The chartplotter system can be no more accurate than its charts. Without charts that are accredited by appropriate governmental organizations, a chartplotter is an example of an Electronic Charting System (ECS). When the charts meet the technical requirements of the International Maritime Organization (IMO) and national hydrographic bodies, the chartplotter can qualify as an Electronic Chart Display and Information System (ECDIS). ECDIS legally can be substituted for paper charts while navigating in active waterways, but vessels are required to maintain paper charts if their chartplotter does not use ECDIS.