Just got a new boat and some electronics! I ordered 798ci HD SI on sale to put on the bow. I saw 859Ci DI with a naviontics map card at Bass Pro Shop. I have a of question. Is Navionics better than the Lakemaster chip? 

The best map software is the one that has the coverage you want with the detail you want.

 

For a particular body of water that Navionics covers and Lakemaster covers in HD, the Lakemaster is better.

Lakemaster HD has depth highlighting, water level offset and can operate an iPilot Link Minnkota electric steer trolling motor using the Follow-the-Contour feature.

 

You can view the Navionics maps on-line with the Navionics web site's Web App.

You can get the Lakemaster lake lists on the Humminbird/Lakemaster web site.

 

The Navionics map card in the sale package is the Navionics+ version. That has no maps, You choose what locations to download to the map card from anywhere in the US and Canada. There is no regional restrictions like Lakemaster has.

 

For the 798ci HD SI Combo, you should use a transducer that is suitable for trolling motor use instead of the included transom Compact SI transducer.

That would be the XTM 9 SI 180 T Compact SI PUCK or the XTM 9 HDSI 180 T.

Both of those have extra internal shielding to help with possible RFI from the trolling motor.

The HDSI will produce a sharper image due to its longer SI crystals.