I have a new to me Navionics chip. Can anyone tell me how to see what lakes it has on it? It says south and has several states listed. Fork is pretty detailed but nothing really for Tawakoni etc. Thank you

Looks to be a S6 card which is the latest version on Navionics card. Tawakoni is a relatively flat on the main lake until you get to the points ect.

Thank you. I wasn't sure if Navionics had boat lanes, timbered areas and that stuff.

Google “Navionics South lake list “

You will navigate to the web page below

Click on lake list link and select Texas

Navionics map cards have been version 6 since 2010 when the Freshest Data Updates program started==annual subscription.
What is on a map card is the data that was available when the card was made---Feb 2018.
Since it can be updated, what you see on the Navionics website's Chart Viewer can be on the card today if you update it today.
Since the data is that old, you would have to renew the Freshest Data subscription to do an update.

Exactly, if the person you bought the card did the updates properly, you'll have static data that is fairly reliable. You may want to consider updating anyway as there are overlays that you can add that make the map views much more useful. Navionics is constantly taking sonar logs and feedback to expand the coverage of many lakes. However, Tawakoni as they say is really a flat bowl.