There's 2 things to do.
1. Settings/ Networking / Data Sources... then select, the SONAR and see what Water TEMP says? Over on that same line is a little TRIANGLE, you select this and it will say GLOBAL or LOCAL. You'll want to select LOCAL.
2. To simply ADD any overlay to your screen ( or any screen ) you hit the PWR button. The menu will pop up. Select EDIT OVERLAY. I believe on the right side it will have a ADD button. You click ADD and find the TEMP. Then you can change the SIZE or drag it with your finger to where ever you want it. don't forget to hit SAVE when you're done.
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