Transferring Charts from OpenCPN

Many OpenCPN users have been using SEAiq Open because it is the only chart plotting app for iPads that lets you load your own charts. This is a step-by-step guide for OpenCPN users on how to transfer the S-57 or BSB/KAP charts you use with OpenCPN into SEAiq Open. After completing these detailed instructions, you will have all your charts available in SEAiq Open on your iPad.
Before getting started: if you are in USA waters, we recommend trying SEAiq Free, which uses the vector charts that NOAA publishes for free. SEAiq Free (like SEAiq Open) is free to evaluate, with an in-app purchase to unlock all of its features. SEAiq Open works great with the NOAA charts, but SEAiq Free has special support for downloading NOAA charts and keep them up to date.
The main difference between SEAiq Open and OpenCPN is that charts are loaded into SEAiq Open using the Apple iTunes program and the iTunes File Sharing feature. iTunes Files Sharing works best if you only transfer a few files, so you first have to put each of your collections of charts into a Zip file and then copy that file onto your iPad. (A Zip file is just a file that can contain any number of other files.)
To figure out which folder(s) you should transfer, run OpenCPN and go to settings by pressing the wrench icon in the bar. Then go to the Charts tab. In the lower box you will see the different sets of charts that you have loaded into OpenCPN, one per line. Go to each of these folders on your laptop. For S-57 charts, look for the ENC_ROOT folder containing a CATALOG.031 file (as well as folders of charts).
To install the charts, you need to be able to create Zip files. If you are using an Apple laptop, it has a built-in capability to create Zip files. If you have a Windows laptop we recommend using free 7Zip ( utility.
Now you have the key pieces in place and can install the charts on SEAiq Open by following these step-by-step instructions.

  • Make sure your laptop is connected to the internet.
  • Attach your iPad/iPhone to your computer with the white cable.
  • Run the iTunes application.
  • Select the iTunes Store on the left hand side of the window.
  • Type "SEAiq Open" in "Search Store" in the right.
  • Install SEAiq Open on your iPad (or iPhone) for free.
  • SEAiq Open initially comes only with a base chart. This is a good time to spend a moment trying it out. Press the Navigate tab and try moving around the world using standard iPad gestures.
  • For each of your chart folders, you need to create a Zip file
    • Windows
      • If you have not done so already, download the free 7Zip utiity and install it.
      • Go to the folder containing the the folder named ENC_ROOT.
      • Right click on ENC_ROOT folder.
      • Select 7-Zip sub menu (if it is not there, then there may have been a problem installing 7-Zip).
      • Select Add to option.
      • Wait for the Zip file to be created. This can take awhile.
      • When done compressing, you should now have a file called
    • MacOS
      • Select the folder named ENC_ROOT.
      • Select File from the bar at the top of the screen.
      • Select Compress "ENC_ROOT" (mid-way down the menu).
      • Wait for the Zip file to be created. This can take awhile.
      • When done compressing, you should now have a file called
    • IMPORTANT: You may want to rename the file if you are installing multiple sets of charts because each Zip file you transfer to SEAiq Open must have a different name. If you only use one set of charts, this is not an issue.
  • Go back to the iTunes application.
  • Select your iPad/iPhone on the left side of the iTunes window.
  • Select the Apps item in the upper bar.
  • Scroll to the bottom of the window until you see the File Sharing section. In iTunes on MacOS, the apps listed under Sync Apps scroll separately from the window frame they are in. This can sometimes be confusing. If only the list of apps is scrolling, then you may need to click on the area outside the apps list.
  • Select SEAiq Open in the Apps section underneath File Sharing.
  • Press the Add... button.
  • Find the Zip file you want to install on this iPad/iPhone.
  • Press the Open button.
  • The small activity window at the top of the screen should show the file being copied. Be sure to wait until the copy is complete before proceeding.
  • You should now see your file listed in the SEAiq Open Documents.
  • Return to SEAiq Open on your iPad
  • Press the Charts tab on the bottom of the display
  • Each of your Zip files should be listed along with information about how many charts each contains. If not, press the Help button at the top of the Charts tab and read the Troubleshooting section (toward the bottom).
  • Press the Navigation tab on the bottom of the display.
  • You can now explore all your charts and try out all the features for the 1 week evaluation period.  After the evaluation period is over you can still view all your charts, but many of the other features will be disabled.
  • After you decide you are satisfied with SEAiq Open, you can purchase the upgrade to enable all of its features.
    • Make sure your iPad/iPhone is connected to the Internet.
    • Select the Store tab at the bottom of the window.
    • Press the Buy button.
    • Enter the purchase information.
    • After purchasing the button should read "Installed".
    • You can go to your other iPads/iPhones, install SEAiq Open, and press the Restore button on the Store tab to upgrade those for free.


  1. trying to install CM93 of may2009 on my ipad 2 with no success PLEASE HELP! I just followed the instructions above, made a zip file with my macbookpro, loaded it on itune but it doesn't show in the chart section of SEAiq

  2. I'm sorry you are having trouble transferring the zip file to your iPad. If the file doesn't show up in the SEAiq Chart tab, then it means the file wasn't transferred to that device & app, for some reason.

    Does iTunes show the file as having been transferred under "SEAiq Open Documents"?

    In some cases, you may need to change from the Charts Tab to the Navigation Tab and back in order to see the file show up.

    Perhaps you transferred the file to a different iPad/iPhone or selected a different app?

    My recommendation is to double check all your steps as the instructions are very carefully written. If you are still having trouble, please send an email from the app, using Settings -> Send Us an Email and we'll sort things out. We have 100% success in getting users to load their charts (in the supported formats) onto SEAiq.

    1. Thanks for your reply. I just re-install the app and started all over the procedure... and now it is working... GREAT THANKS A LOT!

  3. On your home page it says this:

    "All our products support both vector and raster charts."
    ...then on the "transferring charts" page it says:

    If some of your charts are raster (BSB) charts, you will not be able to use those with SEAiq Open since it only supports vector-based charts.

    I like my raster charts and for British Columbia they are my only charts. What is the truth here?

  4. Our home page is correct: all our apps support both raster and vector charts. The "transferring charts" is out-of-date in this regard. Thank you for pointing this our.

  5. Does this also work with SeaIQ free? I have purchased SeaIQ free for the special support for automatic downloads of NOAA data can I also import Canadian ENC and Rastor charts this way?

    1. SEAiq Free and SEAiq USA can only use the automatic download/update for NOAA and US ACoE charts. If you want to use other charts, you need to be using SEAiq Open or SEAiq Pilot.