I purchased a Garmin Navionics Vision + SDCard (the new card now advertised to work with new generation Garmin charts). I was happy with my LakeVu G3 Ultra East maps, but wanted similar coverage for coastal areas - mostly mouths of rivers and the intracoastal. All devices I tried this on are EchoMap UHDs with the latest (19.10, I think) software.
I think Garmin's software is not quite ready yet. If I'm ever home during their phone support hours I may call them.. In the meantime I will probably email them an edited version of this post. Here's my story.
When I first received the card, I loaded it into my PC and opened Garmin Express as that always seemed the easiest way to register an SDCard-based map in the past. Express recognized them card but said it could not register the maps.
Next I loaded the card into my 93SVUHD. It recognized the card but said I had to sync with Active Captain to activate it. I did this and the card became visible in my account and I could download maps in Active Captain. Despite multiple syncs, resets, and wipes, I could never get the card to show as "active" in the 93SV UHD. It works fine and looks great in Active Captain.
Next, I put a blank card in my 73SVUHD, leaving the purchased card in my 93SVUHD (these are not networked at the moment because I'm doing this on my bench, they are networked when on my boat). By now I had close to 10GB of maps downloaded in Active Captain. It synced and showed the maps as active on the 73SVUHD. It took about 2 hours to sync 10GB of maps. Then it got stuck at validating at 99%. I let it sit like this for a couple of hours and then cycled the power. It went through validation again and completed after maybe 20 minutes. The device stated the maps were active, but they did not work properly. Even though I had pretty much synced all of North and South Carolina, only a couple of tiles worked and they were corrupted (so they really did not work). The attached photo shows what the corrupt map tile looked like. I tried syncing again and again, but a sync would not trigger, even if (in Active Captain) I downloaded more maps, deleted and re-downloaded maps, or downloaded maps from another package (like my Ultra maps).
I then pulled the original Navionics SDCard from the 93SV and placed in in the 73SV. After following the steps to connect to Active Captain the card showed as active (something that never happened in the 93SV) but the only maps I could see were the pre-installed LakeView maps, so I went back to starting with a blank card again.
Whenever I was not busy this weekend, I'd wipe everything and try it all again. On one of these tries it actually worked when I wiped everything (device and active captain) and only downloaded about 1GB of maps, however, after that when I tried to add more maps and resync, it would not work.
Later, I made two fresh 32GB SDCards and downloaded just my ultra maps in Express, which are about 26GB, leaving a little less than 6GB for me to download some Navionics maps via Active Captain. I downloaded just the coastal areas of NC and SC so my charts would use the Ultra maps for inland and the Navionics for coastal. The sync went as before, hanging at 99% validated. I ended up with the same exact corrupt map tile as the attachment again. All the inland ultra maps still worked, so I can use the charts as they are while Garmin figures this out.
I'm very disappointed that you can't do all the downloading in Express and it just work. At present, I cannot do anything with the Navionics card in express only in Active Captain. Even then, the SDCard would not work. I wonder if this is just the UHD devices or if the same happens in Ultra and GPSMAP.
Finally, I think Garmin knows there are issues because every day the expiration date of my subscription has increased by a day, and they are not going to let our subscriptions get shorter until they deliver a fully working product. Speaking of subscriptions - when I looked at the list of my subscriptions online, it appears the renewal fee will be $99 versus the full initial price.