Navionics Iphone App

[CDMeyer]

I want to download the Navionics Web app, I want to know if when u have no service will it still work and show me contour lines and the general map

[Wayne P.]

Yes, IF you have GPS turned on. BUT you should have a charger hooked up when using GPS.

 

I have a Bluetooth GPS antenna for my WiFI iPad and I can use the Navionics maps just like my sonar/GPS units.

 

The WiFi/Cellular iPads have a GPS antenna.

[Wayne P.]

I also have the App on a couple of Android smart phones and a couple of Android tablets.

[FloridaFishinFool]

I want to download the Navionics Web app, I want to know if when u have no service will it still work and show me contour lines and the general map

 

I thought about using Navionics too, that is until I cross checked their so called "contour" maps with the real world and discovered Navionics contours are no where close to the real world and extremely inaccurate.

 

I regularly fish a lake here in central Florida and I have downloaded the official government bathymetric map used by county governments as well as state government agencies and it is considered very accurate since it was measured by real humans who came to the lake to make an accurate map for government purposes. And then there is Navionics map. No telling where or how they come up with their so called contour lines and depths, but they are not even close and so I did not download it. 

[Scott F]

The same Navionics map website has the most accurate map I've ever used for one of the lakes that I fish. I have 4 different printed maps and 3 different digital GPS maps and none of them come close to the Navionics site version.  Don't condemn the whole site because not every one of the lakes maps it has isn't the best version that exists.

[Wayne P.]

The same Navionics map website has the most accurate map I've ever used for one of the lakes that I fish. I have 4 different printed maps and 3 different digital GPS maps and none of them come close to the Navionics site version.  Don't condemn the whole site because not every one of the lakes maps it has isn't the best version that exists.

 Exactly

 

A lot (if not all) of digital map products purchase maps from other sources along with doing their own surveys.

 

I know for sure that some of Navionics maps are scanned paper maps. I have personally surveyed some of them and had a HD contour map done with the Navionics Sonar Charts program.

Another lake is a USGS outline that I surveyed to get a HD contour map created with Sonar Charts.

 

That example is not a Navionics surveyed location. If it was, it would have 1' contours. It is from "other sources". Not only that the contour numbers are in meters instead of feet.

Use the correct format and it will match the other map, just less contours.

The only number I can make out is 6.1 meters and that is about 20'

[FloridaFishinFool]

***Correction- I made a mistake comparing maps with different measurement formats... I got my feet and meters mixed up, but there are still inaccuracies in map comparisons.

 

So exactly how do I get accurate contour maps from Navionics for Florida? I just randomly checked another Florida lake and here are the results:

 

This first map is from a government website showing Kingsley Lake in Clay County Florida, north Florida. This map shows the deepest hole is 70 feet deep while Navionics says it is only 18 feet deep and completely misses the 50 foot deep hole to the west. At what point should I consider Navionics inaccurate? Just for the heck of it I will now check lakes all over Florida just to see for myself.

 

Kingsley Lake government bathymetric map:

 

 

Navionics so call bathymetric mapping:

 

 

 

 

All I can say is based on these random examples Navionics is not accurate.

[Wayne P.]

So exactly how do I get accurate contour maps from Navionics for Florida? I just randomly checked another Florida lake and here are the results:

 

This first map is from a government website showing Kingsley Lake in Clay County Florida, north Florida. This map shows the deepest hole is 70 feet deep while Navionics says it is only 18 feet deep and completely misses the 50 foot deep hole to the west. At what point should I consider Navionics inaccurate? Just for the heck of it I will now check lakes all over Florida just to see for myself.

 

Kingsley Lake government bathymetric map:

 

 

Navionics so call bathymetric mapping:

 

 

There is a difference of more than 50 feet of depth in the 70 foot hole shown above as only 18 feet deep, and the west hole 50 feet deep is not even shown on Navionics map. Why?

 

All I can say is based on these random examples Navionics is not accurate.

Change the Depth Format to FEET instead of METERS. It's that setting to the right on the map.

Navionics is an international mapping company, it has both formats with their products.

 

The maps on the site is the whole world.

[FloridaFishinFool]

That helped some! But a lot of information and accuracy is missing. In the Kingsley lake map there is no 50 foot hole. Just not there. And with Lake Maitland the bottom contour is no where close to accurate.

 

My only conclusion is Navionics is not as accurate as it should be- at least for Florida.

[RoLo]

My only conclusion is Navionics is not as accurate as it should be- at least for Florida.

 

Unfortunately, no cartographer could possibly provide accurate bathymetry for every lake.

All lake charts have inaccuracies, more so in some lakes and less so in other lakes.

The 'only way' to guarantee accurate bathymetry is to generate your own contour maps.

I have a Humminbird unit, so I use 'Onix AutoChart Live', but be warned that it's very time-consuming.

 

Roger

[Wayne P.]

Some Florida waters are HD surveyed by Navionics.

 

The Kissimmee Chain of lakes. 

Harris Chain also.

That pond known as Big O is one of them.

 

 You have to zoom in to get the HD contours.

[RoLo]

Some Florida waters are HD surveyed by Navionics.

 

The Kissimmee Chain of lakes. 

Harris Chain also.

That pond known as Big O is one of them.

 

 You have to zoom in to get the HD contours.

 

Actually Wayne, the Navionics HD contours for Lake Kissimmee are badly skewed,

but are far superior to LakeMaster cartography, which is new to Florida and laughably inaccurate.

 

Roger

[Wayne P.]

The Navionics contours in Lake Kissimmee are badly skewed Wayne,

but are far superior than LakeMaster cartography, which is new to Florida.

 

Roger

Have you checked Nautical Charts and Sonar Charts at Kissimmee?

 

I would assume some boaters contribute to the Sonar Charts program to correct any inaccurate data IF that area is accessable via boat.

Sonar Charts does the same as AutoChartLive, just Navionics processes the sonar logs and it is shared.

[RoLo]

Have you checked Nautical Charts and Sonar Charts at Kissimmee?

 

I would assume some boaters contribute to the Sonar Charts program to correct any inaccurate data IF that area is accessable via boat.

Sonar Charts does the same as AutoChartLive, just Navionics processes the sonar logs and it is shared.

 

Yes, my update privilege is still pending, so I update my Navionics Plus SD card before every outing.

Each update imports the latest 'Sonar charts', 'Nautical charts' & 'Community edits'.

Living just 25 minutes from Lake Kissimmee, I regularly get to see the broad discrepancies

between Navionics HD contour lines and the real world as displayed by 3D downscanning.

 

Roger