From what I know, very recently (within a couple of years), the Navionics lake data was based off of Bizer.
I don't know if they still contact Bizer for update info or not, but within a couple of years ago, Bizer was involved in their chart data somehow.
I feel very comfortable using Navionics on the lake on my Raymarine chart plotter.
I also like that they tend to listen to and implement changes if you send them a report of a problem with their charts. At first I thought they would ignore reports of errors on the lake, but they took a few of my reports and implemented them fairly quickly.
So if you see an error in the Navionics chart, instead of just looking at it and shaking your head, send them a problem report and help to make the charts better.
You also can review their chart data online via their 'web app'. This makes it nice if you are at home and want to check a route, or an area. It's also easy to report errors.
If you have their update subscription, they will fix it, then you can update your chip for your GPS Chartplotter too. It's a nice system!