Your unit will read Lakemaster and Navionics products.
No they are not the same.
You can see the list of waters covered on the Humminbird Lakemaster website.
You can view the actual current maps on the Navionics website's Web App. The Web App will have Nautical Charts and Sonar Charts to view. Nautical Charts is Navionics data. Sonar Charts is user generated data.
The Navionics Hotmaps Premium South region, Navionics Hotmaps Platinum South region, and Navionics+ versions have the exact same maps if updated the same day. All Navionics products include a year of Freshest Data updates.
Humminbird Helix 12 SI, 1198c SI, 1198c SI, ONIX 10 SI NT, 360, RC-1