How to download and use a custom C-MAP Genesis map in your sonar/GPS unit (2024)

The key feature of C-MAP Genesis service is the ability to make your own contour charts of any waterbody on which you fish, cruise or sail, and use it on the sonar/GPS unit on your boat.*For anglers, especially, the benefits are revolutionary — not only can you create custom fishing maps with 1-foot contours of waterbodies for which there’s no other map in existence, but you can also improve contour detail on previously mapped waters, and discover and dissect spot-on-the-spot areas overlooked by other anglers.

But before you start catching more and bigger fish with custom C-MAP Genesis maps, you’ve got to get those maps onto the compatible* sonar/GPS unit on your boat. This article will cover the step-by-step process to download to an SD card and load into your sonar/GPS unit the custom maps you’ve made with sonar data you’ve recorded yourself. If you’re not ready yet to record sonar data and create your own custom maps — and would rather download free Social Map charts community-sourced by other anglers in the C-MAP Genesis community, read this article.

The first step to creating custom maps of your favorite waters is creating a free C-MAP Genesis account. To start using C-MAP Genesis charts, visit the website at www.genesismaps.com and click the blue “Sign Up Free” button (as seen in the image below).

The second step is recording sonar logs on your favorite waterbody with your sonar/GPS unit. To refresh your memory on how to do that, watch one of these videos: Lowrance Elite sonar-recording tutorial; Lowrance HDS Gen3 & Gen2 touch tutorial.

The second step is uploading your sonar-log files to your C-MAP Genesis account. The videoat this link enumerates the steps to accomplish that.

If your waterbody of interest is larger than a pond, you’ll most likely need to merge into a master map multiple sonar logs recorded in numerous trips on the water on separate days. You can read this article to remind yourself how to merge sonar logs into a comprehensive map.

The final step is to download your custom C-MAP Genesis map(s) to an SD card and use it(them) in your sonar/GPS unit on the boat. Follow these steps to do so:

1. Insert a blank SD card into your computer’s card-reader slot
   • If your computer does not have an SD-card slot, you will need to purchase an external card reader that plugs into a USB slot on your computer
   • If you are using an HDS Gen3, Carbon, Live or an Elite unit, you must first insert a MicroSD card into the empty slot in an SD-card adaptor, or use a USB-slot adapter that will accommodate a microSD card
2. Log-in to your C-MAP Genesis account and open your C-MAP Genesis Dashboard
   • Don’t remember how to do that? Read this article to refresh your memory.
3. Open the trip or merged map that you wish to download to an SD card to use on your boat
   • A list of every waterbody on which you have recorded and uploaded a sonar log will be the page/tab that your C-MAP Genesis dashboard defaults to. This is the “My Uploads” tab
     • If you want to download the map of a single trip, click the gray down-pointing arrow located to the left of the name of the waterbody you’re interested in
       • This will open a drop-down menu of all your individual trips on that waterbody
       • To open the map of any single trip, click the dark-gray button labeled “view trip”
     • If you want to download a merged map, first click the light-gray tab labeled “Merged Uploads” at the top of your dashboard
       • A list will display of every waterbody for which you have merged the sonar logs from multiple trips into a master map
       • Click the gray, down-pointing arrow located to the left of the name of the waterbody you’re interested in
         • This will open a drop-down menu of all the merged maps you made of that waterbody
         • To open a merged map, click the dark-gray button labeled “view trip”
           • Note: If you’ve made multiple merged maps for a particular waterbody, you can determine which one is which by clicking the small thumbnail images of the waterbody on the left-hand side of the drop-down list
             • Clicking a thumbnail will open a window that displays the individual track lines that are mapped out in the merge
4. After your map loads, click the “Map Generation” tab (5th tab from left) at the top of your dashboard window
5. In the “Target Device” drop-down menu (located under “Map Options” in the middle of the page), select the sonar/GPS sonar unit in which you will use your downloaded map
   • Haven’t registered your sonar/GPS sonar units (AKA “chartplotters,” “MFDs,” “plotters”) yet? Click HERE for step-by-step instructions.
   • You can register as many as four separate units
6. In the “Include Layer” drop-down menu (located under “Target Device”) choose what, if any, additional layers you’d like to display on your map. You have three choices:
   • 1. “Contours Only” — Will show only your blue-shaded depth contours with no additional layers
   • 2. “Vegetation and Contours” — Will overlay onto your blue-shaded depth contours all the areas of vegetation* you mapped
     • This layer will display only in areas in which your boat speed, while logging sonar, was slower than 12 mph
     • Only areas in which vegetation comprises more than 20% of the water column’s biomass are mapped
   • 3.“Composition and Contours” — Will overlay onto your contour lines a color-coded representation of the size, shape and location of areas of different bottom hardness: dark orange areas show the hardest bottom; a lighter orange indicates the next-hardest bottom; tan is the next-hardest bottom; and pale yellow shows the softest-bottom areas.
     • This layer will display only in areas in which your boat speed, while logging sonar, was slower than 10 mph
7. After making all your selections in the drop-downs explained above, click the light-gray button labeled “Generate”
8. Next, click the gray button marked “Download Map.”
   • While the map file is downloading, you’ll see a rotating progress icon floating in the middle of your dashboard.
9. Once the progress icon stops rotating, you will get the message “Successfully Generated Map! CLICK ‘SAVE’” … below that message will be a light-gray button labeled “Save” … Click that button.
10. If you’re using a PC, after clicking “Save” a box will open allowing you to choose where you want to save the file
    • Choose “SD (D:)” — you’ll see it listed under “Computer” in a vertical menu of options to the left-hand side of the window that opened
    • Type in the name of the waterbody and, if applicable, what additional layer it contains, like this: “Long_Lake-with-bottom_hardness.exe”
      • Don’t make any changes in the next field, “Save as type” — leave it asis
    • Click the “Save” button
    • If your web browser is Chrome (which we recommend) you will most likely see, in the bottom left-hand corner of your dashboard, a small, red circle with a white dash in it, next to a message like this: “Long_Lake-with-bottom_hardness.exe is not commony downloaded and could be dangerous”
      • To the right of that will be a white button labeled “Discard” — do NOT click that button
        • To the right of that “Discard” button will be a small down-pointing arrow. Click it to open a dropdown then hover down to and click the word “Keep” … proceed now to Step #13 below
11. If you’re using a Mac, as soon as you click “Save File,” a compressed/zipped folder containing your map files will download to a pre-ordained spot on your computer, most likely your “Downloads” folder
    • If you have not manually re-set your downloads to be saved somewhere else, it’s going to be in your “Downloads” folder
    • The folder that downloads WILL NOT display the name of the waterbody — it will be named like this: “d254d90f-b3bf-41b7-b636-7c3204d0c0a3.zip (the code will be different for every waterbody)
      • You should re-name that folder now with the name of the waterbody and, if applicable, what additional layer it contains, like this: “Long_Lake-with-bottom_hardness.zip”
12. Before your map files will work inthe Lowrance, Simrad or B&G sonar/GPS unit(s) on your boat, you must first extract the files (PC terminology) from the downloaded .exe folder/file or unzip the folder (Mac terminology) in which the map files are located.
    • Depending on what kind of computer you are using, follow the PC-file-extraction or Mac-file-unzipping directions at the bottom of this page and then proceed to step #14 below
13. Remove your SD card from your computer’s SD-card slot (or external card reader)
14. Insert your SD card into a card slot on your Lowrance, Simrad or B&G sonar/GPS unit while the unit is turned off
    • If you have a unit with two card slots, it does not matter if you use the top or bottom, or right or left slot
15. Turn on your sonar/GPS unit
16. Soon after your unit powers up, a dialog box will open and ask if you want to load the map that you saved onto your SD card — it will reference the waterbody by name
17. On a HDS Live, Carbon, Gen3 or Gen2 Touch unit, simply touch the button that is labeled “Yes”
    • On non-touch Gen 2 units and Elite units, press the appropriately pointed arrow on the circular keypad in order to move your cursor to “Yes”
    • Once “Yes” is highlighted, click the button labeled “Enter”
18. Your map will then almost immediately load onto your unit’s map-display screen for your review
19. Study your map and pilot you boatto where you’d like to fish

PC instructions

If your computer is a PC, follow these steps toextract your map files from the .exe file/folder you downloaded and saved to blank SD card

1. Double-click the .exe file that you downloaded/saved to the blank SD card in your (D:) drive
2. After double-clicking, a dialog box will open— just click the “Enter” button on your keyboard (or, you could click the “Extract” button), and your map files will extract and save themselves onto your SD card
   • A total of five (5) additional files will extract and save onto your SD card. In addition to the original file you downloaded (the one with the .exe extension), you will see new files labeled exactly like this (depending on whether you use a Lowrance HDS or Elite unit):
     • at5.xml
     • permits.txt
     • HDS_Large.at5 (or Elite_Large.at5)
     • HDS_Medium.at5 (or Elite_Medium.at5)
     • HDS_Small.at5 (or Elite_Small.at5)
   • ALL 5 of those files must be onyour SD card for your map to display on your sonar/GPS unit.
3. At this time, we recommend creating a new folder on your computer, naming it “Lake Map Downloads” (or similar) and then dragging the .exe file off of your SD card and into that folder.
   • The .exe file is not necessary to display the maps once the file map files are extracted from it
   • However, it’s a good idea to save the original .exe file for each map you download
     • Because if you should ever misplace the card onto which you saved the five map files detailed above, you can re-extract those files back onto another SD card at a later date, without having to download a fresh .exe file
   • This is an especially important back-up process if you are traveling to fish in a remote area in which you will not have Internet/wifi access
4. Proceed to Step #14 above

Mac Instructions

If your computer is a Mac, follow these steps to unzip the folder you downloaded and access your map files:

1. Depending on your Mac’s operating system, your map’s file folder might un-zip itself while downloading. If it doesn’t, proceed to step #2
2. Double-click the zipped folder
3. A progress bar will briefly appear on your screen as the folder un-zips. Once that progress bar disappears, your unzipped folder will appear in the same folder that the zipped folder is located (in most cases, your “Downloads” folder, as explained above previously)
4. After making sure your SD card is inserted into your computer’s SD-card slot (or external card reader) find the icon for your SD card on your desktop and drag the five files in your unzipped folder onto your SD card
   • Rather than dragging and dropping, you could also copy and paste the five files in your folder onto your SD card.
   • The five files should belabeled exactly like this (depending on whether you use a Lowrance HDS or Elite unit):
     • at5.xml
     • permits.txt
     • HDS_Large.at5 (or Elite_Large.at5)
     • HDS_Medium.at5 (or Elite_Medium.at5)
     • HDS_Small.at5 (or Elite_Small.at5)
5. Proceed to Step #14 above

* To use C-MAP Genesis maps on the water, you’ll need a compatible Lowrance, Simrad or B&G chartplotter.

PublishedJuly 6, 2017April 30, 2020