GPS Position...so far off?!

[Bartableman7]

Both my Garmin and my Navionics boating app put my boat about 50 yards onto the shore. ( In the same place.)   I'm fishing parallel to the shore about 50 yard from shore in 12 feet of water.  What's with that?

[MN Fisher]

If it was just one of the two, I'd suspect a problem with the GPS in the unit - as it's both, I suspect a mapping error.

 

Do an update to the maps - the ones in your units memory might be from when the water was low...especially if the lake you're fishing is a reservoir.

[Bartableman7]

Man made coal plant cooling lake.  Water level is nearly the same every day since it is pumped in for constant level.  High walls on edges.  This lake never changes shoreline and can't.  So odd.  I'll post pics next time I'm there... if it's the same problem.

[TnRiver46]

I know a place like that too

[cyclops2]

Always carry a plastic coated depth map.  And flashlight if you are out in dark days or night..

The GPS system has to many steps to always be correct or reliable. Human memory is far more accurate.  Until you age like me.   

[desmobob]

I have the same experience with my Garmin on the southern part of Lake Champlain.  In my case, the charts and location are dead-on most places, but going under the railroad trestle outside of Whitehall, NY and running up East Bay (lower part of the Poultney River), it shows me as being up on the bank!

 

I've used the mapping feature to try and correct those areas of the maps, but it sure takes away any confidence I had in the maps as far as navigation and safety goes...

[newbiedmv]

I've had the

Same issue with my Garmin e trex before the display got broken. I really Don't know if it was off or the map was off.

[king fisher]

GPS is not off, your charts are off.  Not much you can do other than try another chart.  If you fish the place often, you will soon have waypoints and trails marked to use as navigation points as well as fishing holes.  Some of my best tuna fishing spots are in the middle of an island according to the chart.  I have guests ask me all the time where we are at, and they get a surprised look on their face when I show them we are a mile on land according to the screen.  You can try an updated version of the chart software, but you may simply have to get used to driving your boat on land.  Be careful around islands.  It can get confusing when the chart shows you are on the East side of an Island when really you are on the West side.  I know a guy that drove straight in to an island one night making that mistake.  He had a waypoint marked where he fished, and thought he could drive straight to it.  Island only came out of the water a few feet.  He didn't' see it, and the chart showed him on the other side.  If you are careful, and remember your chart is off you get used to after awhile.

[WRB]

GPS is usually accurate within 3’, maps can be off a lot.

I was fishing with a new partner showing him a few spots as a backseater. I pointed to a spot I knew well from years past, the lake is down 50 vertical feet the map showed the area as an island at full pool. We were in the middle of the lake never was a island there, will be when the lake goes down another 30’. Use your eyes to know you are on water not ground. 

Bottom line map error not GPS.

Tom

[Boomstick]

Go into your settings and turn WAAS/EGNOS on. I had some issues in some lakes where it showed me paddling along the shore sometimes about 100 yards away from where I actually was until I turned that on.