Manually entering waypoint locations is often used by mariners to transfer and share data from one device to the next. If a waypoint is manually entered into a Garmin Marine Chartplotter and the location of the point does not appear where the point should be, please consider the following.

Often, manually entered waypoints can appear incorrect because the Position Format or Map Datum that the device is currently set to does not match the Position Format or Map Datum that was used to create the waypoint originally.

Position Format is the way in which the GPS receiver's position will be displayed on the screen. Commonly displayed as latitude/longitude in degrees and minutes, with options for degrees, minutes and second, degrees only, or one of several grid formats.

Map Datum is a math model which depicts a part of the surface of the earth. Latitude and longitude lines on a paper map are referenced to a specific map datum.

It is required to find which Position Format and Map Datum was used when the original waypoint was created, then change the chartplotter/sounder to match these settings. Once these settings are changed on the chartplotter/sounder the waypoint can be created and the location of the waypoint will match the waypoint's original location.

If the original waypoint was taken from a map, there should be a legend on the map that will explain what Position Format and Map Datum was used to create that map. Most often this is found near the map key.

For more information on changing the Map Datum or Position Format settings on the chartplotter/sounder, please refer to the Owner's Manual for that device.