I have used Ethernet between HB 998 si and HB 899hd si. I can share waypoints as well as transducers. Since my transducer in front is 2d I have to use the back transducer if I want to use di view. I can change the setting on unit to use either transducer as well as share gps and waypoints from either unit.
I think your 858 unit is down image and 2d only and should be up front and use the 899 hd si unit on the console.


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