Manually Entered Waypoint Appears in the Wrong Location on the Chart

Mariners often manually enter waypoint locations 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 to be the location it should be, please consider the following.

Position Format or Map Datum

Position Format is the geographic location on the map. There are different formats on the Garmin chartplotter the most commonly used positions formats are: 

• hddd°mm.mmm'
• hddd.ddddd°
• hddd°mm'ss.s

These position formats display as latitude/longitude in degrees and minutes, with options for degrees, minutes, seconds, or degrees only. There are also several grid formats. Manually entered waypoints appear incorrect because the Position Format or Map Datum does not match the Position Format or Map Datum used to create the waypoint. Waypoint data coming from another chartplotter: check the position format and map datum from the original chartplotter. If the waypoint is coming from a purchased chart check the legend of the map. 

Map Datum

"A geodetic datum is an abstract coordinate system with a reference surface (such as sea level) that serves to provide known locations to begin surveys and creat maps. In this way, datums act similar to starting points" source reference NOAA 

Check the original source of the waypoint data for the map datum used, match the Position Format and the Map Datum on the chartplotter that waypoint data is entered.  

Once the correct position format and map datum are set, entered waypoints will match the original locations.

For more information on changing the Map Datum or Position Format settings on the chartplotter, refer to the Owner's Manual.