Navionics Premium hotmaps North / Canada 08 chip question

[guidedfishing]

I have a question if some one can answer or one of the Navionics guys can help with. I have used Navionics chips and never had an issue. I purchased the north chip because I need only one lake> "Abamategwia" in Ontario. The contour level was fine and was not expecting much more than the 10 feet but my problem or question is why would my Latitude and Longitude be off by almost 400 meters, is there something I am missing. This was in a Lowrance 522 which has not been a problem with any of the other chips. I also verified the lat and long with my backup Garmin handheld mounted 12 in's away. Both tracked right on but the map was clearly off, so a good part of the time instead of the GPS showing me on the lake I was traveling on land (according to the navionics chip) I have never seen a chip off this badly and hope I am off base here. Any suggestions?

Has anyone else had an experience with this amount of error in a Navionics chip, or the Canadian North chip? was there a fix?

I hope I am missing something simple here.

Tnxs
GF

[Larry Carr]

Guided,
Larry Carr here from Navionics. Couple of questions for you and then I'll do some research

Where is the Lowrance mounted and where is the GPS antennae mounted?

What version software in the Lowrance?

On the satellite page, how many sat's are showing as locked on.

I'm not saying the chart is perfect, but I've had fishing friends and pro's that use the chart tell me it is spot on in that area, so I want to do a detailed checkup to get all the variables that might be effecting the performance of the 522.

Larry

[guidedfishing]

Hi Larry thanks for the follow up.

The LMS 522c iGPS is mounted on a ram mount that puts the top of the GPS almost flush with the wind shield on the single console. There are no other items above the GPS. The antenna is internal to the unit I have never experience any problems with this unit locking on very quickly, I have never experience this unit losing satellite contact once locked on. I have used the unit with the Lowrance base maps and the Navionics Wisconsin chips and they have been spot on very satisfied.

The Software version is the following

Version: 2.4.0
Build: LN8455F
Build: LL1211C
STV: 1.0

The unit was locked on to a minimum of 4 satellites 90% of the time there were some occasions were I did see the number go to 3. The deviation in the path did not change when 4 or more satellites locked on verses the 3.

I still have the last trail that shows the deviation from the actual lake map, unsure what value that could provide or how I could make it available as to provide any additional insight.

I was also running a hand held Garmin co-located with the 522. The Lat and Long for both units were tracking at the same coordinates.

I am heading back in next Friday so if its as simple as a setting that would be great.

Thank you
GF

[guidedfishing]

Well, I took the time to calulate my trail, compared it to the physical map of the area and then the deviation from the shore line to the actual plot on the Navionics chip. It was approx 420 meters of deviation. I can find no system tool on the application menu of the 522 to account for this. The Lowrance 522 matches the physical map and the garmin lat long coordinates. I can only draw the conclusion that for this particular lake the Navionics map chip is off no less than 400 meters.

I will validate against another lowrance and bird next week when in the area and report.

at this point disappointed but will give it another fair shake before I write it off to a wasted $100.00

good luck
GF

[Larry Carr]

Guided,
Keep me posted when you get the info. My e-mail is lcarr at navionics dot com.

Larry

[guidedfishing]

Well, after a couple more weeks in Canada, and running the chip in a Bird as well I comfired that 08 canada chip at least for this lake is not even close. The Bird had the same 400 meter plus deviation same as the lowrance and garmin.

Larry if you can tell me the 09 chip used different datum then I will consider it. Otherwise this chip is virtually useless, and down right dangerous.

Since I only need it for this lake I will gladly return it for a refund.

good luck
GF

[Larry Carr]

Guided,
Can you get me a quick lat long on that area and I will check the 09 chart.

Larry

[guidedfishing]

Hi Larry,

Here are the latitude and longitude. This will put you on the lake.

49 40' 52" N
91 54' 10" W

Thank you for the feed back

GF

[brant]

guided,
I too have the same chip and was fishing LOTW, just south of Kenora last year. I found that my chip was off several feet to several hundred feet, depending were I was. I hope you get better results than I did! I emailed Navonics with my chip information and my complaint. I was hoping I had a fluke chip, but the lady that responded said my chip was "within their tolerances." I was disappointed for the amount of money they cost and the cost to upgrade to the new ones.

[guidedfishing]

Brant,

The one thing that was consistent between the Bird and the Lowrance was that it was off by 400 METERS pretty much anywhere I was and this was with 3D and WAAS coverage, and anywhere the guy running the bird went. In fact I had just told him to try it and he got a little carried away watching his GPS in less than clear weather and just about ran his boat into the shore line... Needless to say I recieved the chip back that afternoon he was not impressed..

If 400 meters is acceptable, over 1300 feet well you get the point. The GPS is capable of less than 50 feet at almost any time and that is what I expect to be the minimum acceptable. Its a map and it should be spot on or whats the point.

waiting to see what Larry comes back with. either way the chip I have is useless.

Now I have a Wisconsin chip that I have found to be fairly accurate (but that is what I paid for)

Thanks for the feedback
GF

[guidedfishing]

Larry,

Any opportunity for feed back on the comparison of the 08 datum to 09 for this lake.

Thank you
GF