How to create your own custom-colored depth ranges on C-MAP charts


At a glance, C-MAP chart users can more quickly identify dangerously shallow areas, more efficiently troll the most productive portions of the water column, and more easily find fish-holding high spots and holes.

All that and more is possible thanks to a feature that allows the users of select C-MAP charts* to choose and set custom color palettes to highlight multiple depth ranges on the contour maps they use on their compatible Lowrance and Simrad sonar/GPS units.**

It’s said that at any given time, 90% of the fish are in 10% of the lake — with this new feature, you’ll be able to easily highlight that fish-holding 10% on your map and catch more and bigger fish.

For the sake of example, we’ll imagine a use-case scenario in which we’ve determined, after three consecutive days of practicing for a late-summer bass tournament on Minnesota’s Lake Minnetonka, that largemouth bass are biting in 12 to 17 feet of water and that smallmouth bass are biting in 21 to 27 feet. To help us more easily target those “fish here” depth ranges in our hypothetical tournament, we’re going to customize them with the attention-grabbing colors of gold and magenta. And to help us prevent shearing off our lower unit or getting stuck, we’ll use a custom red color palette to highlight a no-go/danger depth range.

Here are a few examples of what your C-MAP Genesis maps will look like after applying custom color palette depth shading, compared to what they look like without custom shading (article continues below images):Custom_Contours-Humps-2-panel-widest-zoom-COLLAGECustom_Contours-Humps-2-panel-wide-zoom-COLLAGECustom_Contours-Humps-2-panel-COLLAGE

We created the custom color palette depth shading shown above by following these steps:

  1. If you have not already, download and install onto your HDS sonar/GPS unit Lowrance’s most-recent software update
    • Not sure how to update your sonar/GPS unit’s software? Learn how HERE.
  2. Insert into your compatible HDS unit a Precision Contour HD card or a mini-SD card onto which you’ve saved the requisite files to display a custom-made C-MAP Genesis map or a free C-MAP Genesis Social Map chart
    • Don’t know how to make and download a custom C-MAP Genesis map? Learn how HERE.
    • Don’t know how to download a free C-MAP Genesis Social Map chart? Learn how HERE.
  3. Push your “Pages” button
  4. Select “Chart” (Steps 5-7: See image below)
  5. Select “Chart Options”
  6. Select “View” (Note: This step is not applicable to HDS Live units — after selecting “Chart Options,” simply scroll down to the bottom of the vertical menu, where you will finding the “Shading” button)
  7. Select “Shading” (NOT “Depth Palette” – that’s a different feature)
  8. Select “Custom” (NOT “Depth 1” or “Depth 2” – we’ll get to those later in this article) Custom_Depth_Shading-Slide
  9. In the “Custom Shading” window that opens, select “Depth 1” (top-left corner) to highlight the text/box.
  10. Select “0” in the top-left corner entry box* (see image below)
    • This will be found under “Depth (ft.)” – the first (from left) vertical column in the “Custom Shading” window/page
    • Note: Although this entry box initially defaults to “0,” after you use this feature, it will subsequently default to your previous settingstep 9
  11. In the “Edit” window that opens, select the default number in the “Depth (ft)” entry box. It will have 5 digits, like this: 00000  (See image below)step 10 IMG_2340
  12. Using the buttons in the onscreen typewriter-style keypad that opens, arrow over to the right, through the zeroes, until your cursor rests where you want to set the TOP END of the shallowest depth range you’d like to set, using the on-screen key pad to enter the appropriate number(s) (see images below) 
    • If, for example, you’d like to set a no-go/too-shallow depth range of 0-3 feet for a bass boat, you’d set the numbers in the first box like this: “00003”step 11 IMG_2341step 11d IMG_2344
  13. Select “OK” at the bottom-left of the number-entry screen (see image below)step 12 IMG_2345
  14. Your screen will return to the “Edit” window, where you should now select the bar of color to the right of the word “Color” (see image below)step 13 IMG_2346
  15. In the vertical stack of color bars, drag your finger down the screen until you come to the color you would like to assign to your first custom depth range. In this example, we’re looking for red, which is not visible on screen at first, but will be visible toward the bottom, when you drag your finger down the screen (as shown in the GIF below).step 14 IMG_2350
  16. If you want to leave the opacity of your first custom depth layer at 100% (that is, you don’t want it to appear transparent at all), click “OK” at the bottom-left of the “Edit” window (as seen in the image below) and proceed to Step 19.step 15 IMG_2351
  17. If you want to change the opacity of your first custom depth layer to less than 100% (that is, make it transparent to some degree), click the number in the box to the right of the line item “Opacity (%)”
    • Note: the number will default to 100 (as shown in the image below), but a different number could appear there later once you’ve re-set the opacitystep 16a IMG_2352
  18. In the vertical menu of numbers (they’re in increments of 10%), select a number to choose the percentage of opacity you want – 70% opacity (see image below) would mean that your layer would be 30% transparentstep 17 IMG_2353
  19. Click “OK” at the bottom-left corner of the “Edit” window (see image below)step 18 IMG_2354
  20. If the next depth range that you want to highlight is numerous feet distant from the top end of your no-go/danger depth (which is likely), you will first need to assign an unobtrusive color to the depth range BETWEEN the top end of your no-go/danger depth and the bottom end of your “fish here” depth
    • This is because the “Custom Shading” process overrides the default blue-scale pattern that your map comes in. Undefined depths will default to the previous depth color, so it’s best practice to manually define the color for each depth range.
    • So the next step is to essentially repeat the above Steps 9-18, but starting in the second box down under “Depth (ft)” in the “Custom Shading” window
      • Initially, this box will default to “40,” but will later default to whatever number you set in any previous customization (see image below)step 19 b1 IMG_2356
      • In our example use-case, we’re setting the lower end of this depth at 4 feet – 1 foot more than the top end of our no-go/danger depth range (see image below)step 19 b2b IMG_2358
        • We suggest choosing one of the lightest blue colors for this depth range (see image below)step 19 b2d IMG_2360
  1. Once you’ve set your 2nd depth-range color, select “OK” at the bottom-left corner of the “Edit” window
  2. Now, we’re going to choose the bottom end of our first “fish here” depth range. In our example, we’re setting, 1. A shallower depth range at which largemouth bass have been biting, and; 2. A deeper depth range at which smallmouth bass have been biting.
    • This number will be entered into the third entry box down from the top, under “Depth (ft)” in the “Custom Shading” window (see image below)step 21a IMG_2362
    • Initially, this box will default to “80,” but will later default to whatever number you set in any previous customization (see image above).
    • In our example, we’re setting the bottom end of our first “fish here” zone at 12 feet. (see image below)step 21d IMG_2371
    • Follow the steps as described above to set a custom color for this depth. We suggest using a stand-out color like bright gold for your first “fish here” depth range. (see image below)step 21d2 IMG_2372
  3. Once you’ve set your first “fish here” depth range color, click “OK” at the bottom-left corner of the “Edit” window
  4. In the next entry box (in this example, the fourth from the top) the number you choose will set both the top end of your first “fish here” depth range AND the bottom end of your next depth range (in this example, the fourth range)
    • In our example, we’re going to set the top end of our first “fish here” depth range – the largemouth bass zone – at 17 feet.step 23a-b IMG_2381
  5. It’s also in the “Edit” window of the “Depth (ft)” entry box from Step 23 above that you will choose the color for your fourth depth range, the bottom end of which is set with your choice for the top end of your third depth range started in Step 21 above (in our example, the yellow, 12-17 foot, largemouth “fish here” range)
    • If your second “fish here” depth range does not abut your first “fish here” range, you’ll need to set a blue-scale buffer range between them. In our example, our largemouth range is 12-17 feet and our smallmouth range is 21-27 feet, so we’re going to choose a darker blue for this buffer zone. (see image below)step 24 IMG_2383
      • If your second fish-here depth range DOES immediately follow your first “fish here” range, you’d want to choose here another stand-out color like magenta.
  1. Now we’re going to set the bottom end of our second “fish here” depth range, as well as choose that range’s color. To do so, we’ll repeat the above Steps 23-24, with a few exceptions: We’ll start in the fifth-from top entry box under “Depth (ft),” we’ll choose 21 feet, and we’ll choose the stand-out color of magenta.step 25 IMG_2405
  2. The final step in our use-case example is to set the bottom end of our second “fish here” depth range (the magenta-colored layer). But we’ve run out of entry boxes under “Depth (ft)” – the default number of boxes is five. However, we can create a sixth entry box (or more). To start this process, select the “Add Point” box at bottom-left of the “Custom Shading” window. It’s located directly under the fifth entry box in the “Depth (ft)” column. (see image below). This will open a new “Edit” window.Step 26 IMG_2355
  3. In our use-case example, we’re going to set the bottom end of our second “fish here” depth range (the magenta-colored layer) at 27 feet. To do so, follow the steps you learned above. … And since in our example, we’re not interested in any depths beyond 27 feet, we will set the color in our sixth entry box at white (see image below). This will white-out all the depth contours from 28 feet out to the lake’s deepest pointstep 27 IMG_2406
  4. Once you’ve set as many custom depths as meet your needs, select the encircled X in the top-right corner of the “Custom Shading” windowstep 28 IMG_2416
  5. After you close out of the “Custom Shading” window, your unit will return to your map, with the vertical “Shading” menu (a sub-page of the “View” menu) displayed  To enable the custom-shaded depth ranges you just created, select “Depth 1” in the menu (see image below).IMG_2417
  6. Wait a few seconds, and you’ll see your map display yourustom-shaded depth ranges (as shown in the GIF below).IMG_2419
  7. Go catch a bunch of big fish!

* Custom Depth Shading works on select waterbodies on C-MAP Precision Contour HD cards, C-MAP Lake Insight HD cards, C-MAP Genesis charts and coastal C-MAP MAX-N+ cards.

** Compatible units include Lowrance HDS Live, Carbon, Gen3, Gen2 Touch and Elite Ti models, as well as Simrad NSS, NSE and GO models.

5 thoughts on “How to create your own custom-colored depth ranges on C-MAP charts

    1. Custom depth shading is a feature unique to HDS Gen2 and HDS Gen3 units. Elite and HDS units run on different operating systems and custom shading is not compatible with the OS on Elite units.

    2. Justin: Custom depth shading works on Elite TI units, but not on Elite HDI and Elite CHIRPS models.

  1. I really like the feature. Are the displayed depths at current lake level or the lake level/contours of the built in map? If you are fishing a lake that has seasonal fluctuations it would be much harder to set these ranges if the map shows full pool when the lake is down 10.6′.

  2. I can’t create custom-color depth ranges on A-MAP in my Elite 7 Ti . Every time when I open custom made C-MAP Genesis map or C-MAP Genesis social map, button “shading” is not active. What’s wrong?

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