Welcome to the Humminbird Side Imaging Forums kysten09.
You will have the ability to remove the readout boxes on the Left side of your Side Imaging View and have the depth and the temp displayed at the bottom of the screen.
Make sure that you are running software version 6.640 or higher (your 899ci HD Si will be).
Go to the Sonar menus and look for the SI Readouts menu and set it to “Off”.