Great Lakes Bass Fishing Forum

About Fishing Products including Make Your Own => Electronics Talk => Topic started by: Big dreams on September 24, 2012, 03:13:44 PM

Title: GPS issues
Post by: Big dreams on September 24, 2012, 03:13:44 PM
Has anyone encountered issues with GPS tracking not working properly?  Mine shows the arrow moving on land when I am in the middle of small cuts.  It is frustrating to say the least.  I am using the Lowrance HDS8 Gen2 with an old Navionics Hot Maps I think '09.  I assume it is the Navionics chip causing issues because when I switch to the Lowrance map, it is perfect.  Not sure if navionics chips need updating or what.  Seems like it shouldn't be an issue but something is causing this.
Title: Re: GPS issues
Post by: motocross269 on September 24, 2012, 03:34:22 PM
I have had that on MY HB with Lakemaster chips....It is just the mapping and the GPS system off a bit...Sometimes "Drift" will cause that issue also....

Turn on your graph while your boat sits on a trailer and zoom way in and see if you get a small trail after a few hours....

I am not sure how big of cuts that you are fishing but don't forget that recievers are only accurate most of the time to +-20ft....
Title: Re: GPS issues
Post by: Big dreams on September 24, 2012, 03:44:04 PM
I will try that on the trailer.  The cut on Saturday was 100 ' wide and it showed me about 50' on land.  I will go out and try that to see how it goes.  Thank you
Title: Re: GPS issues
Post by: motocross269 on September 24, 2012, 03:52:52 PM
It shouldn't be drifting that much...That is quite a bit.....It is probably the mapping between the unit and software....If I still had my lowrance stuff I would send you a lakemaster chip to try out....

My HB and Lakemaster mapping is off somedays also.....If I am fishing contour lines I can't rely on the mapping and have to idle over the spot to double check that the drop is actually there...I sometimes question the repeatability of my waypoints using the graphics ....I never had to do that with my Older Lowrance X28 and Lakemaster chips..
Title: Re: GPS issues
Post by: Waterfoul on September 24, 2012, 09:17:58 PM
I've owned quite a few chips over the years... in my experience most of them are off a bit because they are all based on the same data.  But some of the new ones are based on newer satellite data.  All the lakes on my Lakemaster chips that are in HD are spot on.  Nearly perfect in all respects.  But on the same chip, the lakes that are not HD are still off just a bit in some places.

Your waypoints however are always right where you set them.  Coordinates don't vary.  GPS declination can vary though... as much as 20-30 feet at times so even though you are right on your waypoint you could be off by the declination your GPS has at that time.  The only ones with spot on (less than 2') declination is the US Militarty... and for good reason.