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Topic: Humminbird Autochart Live maps are awesome!  (Read 2027 times)

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pmmpete

  • Sturgeon
  • *******
  • Location: Missoula, Montana
  • Date Registered: Jul 2013
  • Posts: 1989
I’ve been using Navionics maps on my fish finder for quite a few years, and have found them to be extremely useful, if not essential, when fishing on big lakes and the ocean.  However, while fishing I’ve discovered that the Navionics maps don’t show many lake bottom features.  For example, in an area which the Navionics maps show as a big smooth slope, my sonar and my jig moving around on the bottom may disclose that the area contains a variety of ridges, gullies, pinnacles, and sharp drop-offs which aren’t shown on the Navionics map. And those un-disclosed features often attract and hold fish.

I recently bought a Humminbird Helix 7 fish finder.  One of the reasons I bought the fish finder is because it has a feature called “Autochart Live,” which lets you create your own lake and ocean topographic maps.  I expected the Autochart Live maps to look like the Navionics maps, but hopefully with some additional subtle details visible.  To my surprise, there have been some major differences between the Navionics maps and my Autochart Live maps, my Autochart Live maps have disclosed that the Navionics maps are often very inaccurate, and my Autochart Live maps have revealed some lake bottom features which are very useful when fishing. 

For example, the first picture below is the Navionics map of the top of a mound in Flathead Lake, Montana, which rises from 190 feet to 60 feet.  I put three waypoints on this map.  Because these waypoints are stored on my fish finder, they appear on both my Navionics maps and my Autochart Live maps.  I knew from fishing on this mound that the Navionics map contains some inaccuracies.  For example, the Navionics map shows the top of the mound as being at Waypoint WP006, but the water depth increases as you move west towards WP006.  And I knew that there is a pinnacle, ridge, or hogback at Waypoint WP004 which rises up to 64 feet, but isn’t shown on the Navionics maps. 

The second picture below is my Autochart Live map of the same area, with a 2 foot contour interval.  The Navionics map shows the top of the mound as being at Waypoint WP006; My Autochart Live map shows the top of the mound as being located between Waypoint WP006 and WP005. The Autochart Live map shows a mound at WP 004, and a smaller and lower mound to the southwest where the Navionics map shows only a smooth descending slope.

The third picture below is the Navionics map of another mound in Flathead Lake which rises from an area 180 feet deep.  The Navionics map shows a sharp point at WP019, with a higher area at 85 feet to the east of the waypoint.  I knew from fishing in the area that there is a shallow gully at about 100 feet at Waypoint WP007 which tends to hold fish, but which isn’t shown on the Navionics map.

The fourth picture below is my Autochart Live map of the area, which doesn’t show any point at WP019, or any high area to the east of that waypoint. The Autochart map shows a shallow swale in the slope at WP019, but nothing dramatic.

I’m totally sold on the value of Autochart Live maps.  However, you have to invest some time and effort to make these maps in a kayak.  The fifth and sixth pictures below show the pattern I pedaled in my kayak to make the maps shown in Pictures 2 and 4 below.

You can store about 8 hours of Autochart mapping on a Humminbird fish finder, but if you buy a Humminbird Zero Line chip, you can store a huge number of Autochart Live maps on the chip, which costs about $99.  If you intend to do any more than casual experimentation with Autochart Live maps, you’ll want to buy the chip.

If you have a large Humminbird fish finder with two Micro SD chip slots, you can easily switch between your Navionics or Lakemaster maps and your Autochart Live maps.  A disadvantage of my Helix 7 fish finder is that it only has one chip slot, so to switch between Navionics maps and my Autochart Live maps I have to swap the tiny little Micro SD chips while I’m on the water.  In order to avoid dropping one of my chips down the drive hole of my kayak, I spread out a piece of cloth or a plastic bag under my fish finder before I start swapping my chips.

In a kayak, when the waves build up, the sonar picture of the bottom shown by my fish finder jogs up and down in a sawtooth pattern because my kayak is rising and falling on the waves.  I suspect that a lot of waves would screw up my efforts to map from a kayak, so I have restricted my mapping to calm days.


skayaker2

  • Rockfish
  • ****
  • Since 2010. Formerly known as "skayaker"
  • TAFKAS (The Angler Formerly Known As Skayaker)
  • Location: Seattle
  • Date Registered: May 2018
  • Posts: 104
WOW, that is quite the crisscrossing survey pattern! How did you decided on the spacing of the pattern and how long did it take you to do it? do you have to keep a constant speed or can you vary it? Not sure if any of the recreational fish finders in the market do it, but the impact of the waves and tides (if you were on the ocean) on the bathymetry could be corrected by software integrating the depth, position, date and tide information. Very cool and useful information, thanks for sharing!


pmmpete

  • Sturgeon
  • *******
  • Location: Missoula, Montana
  • Date Registered: Jul 2013
  • Posts: 1989
Humminbird suggests that you stay at a relatively constant speed when making a map.  I chugged along at about 3 mph in my kayak when making the maps shown in my post.  I was trying to make pretty detailed maps of those areas, so I spaced my routes about 50 feet apart. Once you have recorded a map, you can view it at any contour interval, from 1 foot up.  On the maps shown in my post, there are some steep areas which were pretty dark at a 1 foot contour interval, but a 2 foot contour interval was better.

Each time you use Autochart Live you can adjust for changes in the water level so that a map recorded at one water level will be consistent with an adjacent or overlapping map recorded at a different water level.  Flathead Lake is dam controlled, and the lake level is drawn down by nine feet in the winter.  There are various websites which show the exact level of Flathead Lake, such as the one shown below, so it's easy to make the water level adjustment on that lake.  On a lake for which the level isn't available on the internet, you can choose some landmark such as a bolt on a dock piling or the deep end of a boat ramp and measure the water level from that point with a tape measure. Making the water level adjustment on the ocean would be trickier because the water level changes throughout the day with the tide.
« Last Edit: November 21, 2021, 05:17:56 PM by pmmpete »


skayaker2

  • Rockfish
  • ****
  • Since 2010. Formerly known as "skayaker"
  • TAFKAS (The Angler Formerly Known As Skayaker)
  • Location: Seattle
  • Date Registered: May 2018
  • Posts: 104
Thank you again for the information!