What is the Garmin ActiveCaptain application, how does it work?

According to the introduction of Garmin, Garmin ActiveCaptain is a Maps & Navigation app on the Android platform. There is currently a 18.0.877 version released on Feb 25, 2020, you can see the details below.

The free all-in-one ActiveCaptain™ app provides a powerful connection to your Garmin chartplotter, charts, maps and the ActiveCaptain community for the ultimate connected boating experience. Wherever you are, you’ll have unlimited access to your cartography, be able to purchase new maps and charts, and have access to the Garmin Quickdraw™ Contours Community. Connect to the ActiveCaptain community for up-to-date feedback on marinas and other points of interest. Smart notifications¹ on your chartplotter screen keep you connected with everyone else. Plan a trip or pre-fish a lake, and ActiveCaptain will automatically sync with your chartplotter. Even view and control your chartplotter from your smartphone or tablet while you’re on the water.

This app is not recommended for non-Garmin chartplotter owners and is not intended to be a standalone navigational app. The included basemap is not useable without purchasing additional charts/maps.
- OneChart™ lets you access all your Garmin unit pre-load and accessory card charts and maps from your mobile device and purchase new ones
- Receive smart notifications¹, such as calls and texts, on your chartplotter display when paired with the app
- Connect to fellow boaters with the ActiveCaptain community for up-to-date feedback on marinas and other points of interest
- Make, save and transfer routes and waypoints between the app and chartplotter
- Easily upload and download the latest Garmin Quickdraw Contours content from the community
- Download software updates and notifications from the app to your Garmin devices
- View and control your chartplotter from your smartphone or tablet

¹See compatibility matrix - https://buy.garmin.com/en-US/US/p/573254#devices

- In addition to email and text messages Garmin OnDeck users can now also receive push notifications on their mobile device.
- Bugfixes and performance improvements