Navionics - Nautical Chart, Sonar Chart

[mdogdaddy]

I'm planning a fishing trip to Vermilion this summer. It's been many years since I've been up there.

I have the Navionics + app on my mobile devices and have been marking spots that look interesting.  One of the spots I marked was a nice hump surrounded by deep water. There was a big difference between the Navionics Nautical Chart view and the Sonar Chart view. It literally disappeared on the Nautical view but showed on the Sonar View. I then ran the map "update all" and from the Sonar view now it was gone from both views with my marker out in the middle of nowhere.

So I started to look around for other areas that showed a big difference between the two views. (Many areas however do look very similar on both views) I've attached a couple of screen grabs of a spot that has a huge difference. This is on the north side of Pine Island near Matson Island.

The first is the Nautical Chart view, The second is the Sonar Chart View.

I always thought that the Sonar Chart would be the most accurate, they look more detailed, plus according to Navionics the Sonar Chart is "constantly being updated by Sonar Logs contributed by million of boaters."

I'm not really sure if I can trust either?

To anyone who knows this part of the lake, are there really the holes and humps in this area?  One view shows a 52' hole where the other has 15 FOW.

 

[Capt. Quicksteel]

I know that part of the lake fairly well. The Sonar chart is definitely better but I'm still surprised at how inaccurate it is. There are humps etc but they don't have them in the right places.

[AlwaysFishing23]

Sonar chart is going to be more detailed (obviously). As far as accuracy it’s pretty spot on the most I’ve found navionics to be off is a foot or two usually on steep breaks or humps.

[toddrun]

Wow, I just replicated what you show, and I can confirm the same results.  I did not expect that much of a difference.  Crazy.

[JerkinLips]

I also replicated the differences on my Navionics.  I don't know what to trust now.  I was in 48 FOW on Burntside last weekend and my Navionics said I was in 74 FOW, and I wasn't on a sharp break.

[AlwaysFishing23]

JL, I’ve fished burtside multiple times and have noticed that it seems to be off all over the lake. That’s the only place I’ve noticed it though.

[Cliff Wagenbach]

The sonar chart that shows 52 feet is totally wrong!

Probably more like 15' to 20' depth.

The Navionics  is probably closest to correct.

Cliff

[KirtH]

If you see any issues with mapping follow this link they are very good at fixing issues. 

http://navionics.force.com/PlugPlay?cancel=http%3A%2F%2Fnavionics.force.com%2Fkb&l=en

[FishinCT]

Not seeing that when I switch it to sonarchart. I don't have navionics + app though just regular old navionics. For what it's worth I've always been on the navionics setting when I use the phone app on the lake and it's mostly spot on. Actually didn't realize sonarchart existed until now

[mdogdaddy]

2 hours ago, KirtH said:

If you see any issues with mapping follow this link they are very good at fixing issues. 

http://navionics.force.com/PlugPlay?cancel=http%3A%2F%2Fnavionics.force.com%2Fkb&l=en

I actually did follow up on that same  Navionics mapping discrepancy report earlier today. I sent them the same images that I posted here.

More or less just curious to see what the response would be.

It is interesting to see that community sonar readings can be used to improve mapping software but it looks as though it's not quite perfected yet.

[OhioVike]

I have had the app for several years.  The first thing I noticed on the old app, was a series of trenches in North Niles Bay.  I skeptically went out there first thing to check it out and found nothing.  A few years later, their update corrected the issue. Found many other inaccuracies since then.   I would give the app low marks for accuracy but good marks for functionality.  It is a serviceable for scouting, navigating and marking your spots.  I do use it on ice.   I heard that Garmin did a full lake survey last year.  I am looking forward to their product.   It should be good.  

[mdogdaddy]

Garmin acquired Navionics last October.  That could mean some improvements in the future.

If you have the plus version of the app you can get the updates. Every few days I hit update all.

It just about always has an update to download. If Garmin just completed a survey of Vermilion maybe Navionics will become more accurate.

[JerkinLips]

I have the LakeMaster chip on my Garmin GPS.  It doesn't have increments finer than 5 feet but does seem to be accurate.  Anybody else have an opinion on the LakeMaster maps?

[AlwaysFishing23]

My brother has one in his lowrwnce handheld. He’s had that for 10+ years. It seems fine. I do notice navionics is more detailed somtimes but others it’s the opposite. It does it’s job well.

[delcecchi]

1 hour ago, JerkinLips said:

I have the LakeMaster chip on my Garmin GPS.  It doesn't have increments finer than 5 feet but does seem to be accurate.  Anybody else have an opinion on the LakeMaster maps?

I had them for years and other than the 3 foot contours thing, I found them to be pretty good.  Now using Lake insight that was bundled with my Lowrance elite units, and it looks just like the lakemaster data.  No complaints. 

[Cliff Wagenbach]

Both Lake Master and Navionics chips work fine on Vermilion.

Cliff

[mdogdaddy]

Just received this email from Navionics:

Thank you for bringing your concerns to our Cartography Department.   Navionics appreciates your input.  We anticipate an update will be made available by 30 MAR 2018. I will contact you with instructions to receive the update once it has been released. Please do not hesitate to contact us if you have any questions.

Best regards,

Jennifer Pereira
Navionics Customer Service

[OhioVike]

BTW, I do have Navionics+ but I let the app expire because I preferred the Lake Master.  But I will renew my Navionics in the hope that the Garmin influence will improve their maps.  

[mdogdaddy]

On 3/9/2018 at 4:18 PM, mdogdaddy said:

Just received this email from Navionics:

Thank you for bringing your concerns to our Cartography Department.   Navionics appreciates your input.  We anticipate an update will be made available by 30 MAR 2018. I will contact you with instructions to receive the update once it has been released. Please do not hesitate to contact us if you have any questions.

Best regards,

Jennifer Pereira
Navionics Customer Service

Well, in less than a week Navionics followed up on the update.  I checked the Web app since it is an auto update and the new sonar view was there. Who knows maybe they improved on the rest of the lake since it was all charted last year.

 

[toddrun]

Interesting.  I had let my Navionics+ subscription expire, so I went and checked my map for the area above, and it still has the old, incorrect sonar map.  I still get application updates that show up for the app, but obviously that does not include map updates.  And when I go to the Menu and click on updates, it immediately reminds me it is expired.  So when the app is expired, it looks like it is then a static map from the day it expired, no map updates.

[SkunkedAgain]

My Navionics app is so old that it doesn't even have an update option. It talks about having 3G and iphone 4s. I'm on version 5.0.4 with a GeoCore version of 01.00.03.

I assume that I would need to re-purchase the app to get anything useful, but I still find this old version to be helpful.