A chartplotter is an electronic navigation system that combines a GPS receiver with the capability to display electronic charts/maps, enabling the boat owner to continuously monitor the position and movement of his craft in relation to the surrounding physical environment, both above and below the water.

With its integral processor combining GPS data with electronic charts — the accuracy of which influences the efficiency of the system — a chartplotter pinpoints the location of the vessel and can use the GPS data to calculate boat speed and direction, as well as determine the time and distance to the destination or next waypoint. It displays all this data in real time so that a navigator knows exactly where his boat is and where it’s heading, as well as continuously updating its position relative to its surrounding physical environment..

Boat owners often use chartplotters to preload routes that can then be edited at any time before or during the voyage. Some chartplotters allow the navigator to store hundreds of routes at a time for future use. Each route consists of a number of waypoints to assist navigation and avoid hazards, such as shallow rocks or reefs, represented by longitude and latitude references and depicted on a screen to give a visual representation of the boat’s surroundings. Each waypoint is a numbered position and as the yacht progresses past each one the system indicates the distance travelled and course remaining until the next waypoint. It will also show if the boat has strayed off course and provide information to correct the bearing in order to arrive at the next waypoint.

With the combination of GPS functionality and embedded charts, chartplotter have become an essential navigational tool which is relatively inexpensive to buy and easy to install and use on any type of craft. With a single SD card now capable of storing electronic charts. They are remarkably cost-effective.

Today’s chartplotter has come a long way from conventional paper charts and  they often feature a range of additional functions including man overboard markers, zoom abilities and much more.  Manufacturers, however, continue to recommend that boat owners continue to carry paper charts for important areas, in case of power failure.