Upgrading some 5+ year old fishfinders on my Bass Tracker. Getting 2 new HB's professionally installed this weekend. HB 898HD SI at trolling motor and 998HD SI at console. Have a couple questions:1. what's the purpose of connecting the 2 units together with ethernet cable? Don't I still have to buy buy map software for each unit? and 2.Both Lake Master and Navitronics have the same lakes that I will be fishing in Texas. Any suggestions on which is the best or what I should keep in mind when choosing? Thanks! Any other advice for a beginner to this new technology would be greatly appreciated too!

#1, does "professionally installed" include being done by someone familiar with Humminbird Side Imaging and what it takes for the best performance with your particular hull????

Connecting the two units together with Ethernet allows you to see waypoints on one unit displayed on the other in a different color, allows aharing a single transducer if you want to eliminate cross-talk when the trolling motor is deployed, allows sharing Ehternet accessories, allows sharing temp sensors, etc.

No intercommunication connection shares mapping, each unit has to have its own.

Doug can answer your mapping software brand choice question. I don't use Lakemaster (no coverage in my part of the country).

You almost have to interconnect these units. I cannot imagine not having that.

They share waypoints and like has been said, transducers if wanted and one antenna.

I use Ethernet to share waypoints and accessories like iPilot Link and 360 Imaging can be controlled from either unit when Networked via Ethernet. But one thing I like it gives me insurance if I want to use the other GPS Receiver or transducer if I damage one.

LakeMaster has exclusive features like Water Level Offset, Depth and Shallow Water Highlight plus nore. Check out this page on Exclusive Features from LakeMaster: http://www.dougvahrenberg.com/LakeMaster.html

And also Check out the Official NEW Release of MidSouth Region for Texas...some new lakes and new updates!

http://store.lakemap.com/products/634087/MidSouth_States

For the price of a cable, why not would be a better question!

Can't get more simple than screwing one end of cable to one unit and the other end to the other unit...that's it, no updates, nothing, it's that easy and I can't understand why anyone wouldn't do it.

Which map chip?
Depends.....you will need to check which lakes are on each chips.
I have both a Navionics and a LM. If the lake is a LM HD lake it can't be beat. For non-HD lakes I prefer the Navionics. Some lakes are not on LM at all like Lake Dunlap.
I was hoping for HD maps for Lake Dunlap on the 2013 LM chip. Not there yet.