I am sure it is out there somewhere but have searched the site and google and can't find the exact answers that I am looking for. I have a 1197 at the console on my bass boat. I purchased an 899 Si for a different boat but have had a change of plans and decided to mount it up front on my bass boat. Are these two linkable? and when I do that if its possible, will the 899 read off of the same transducer as the 1197 or will I have to buy the trolling motor transducer for up front, and link the two so that all of my waypoints will be the same on both. Sorry for the newb questions, have just fished with what I have and don't keep up with the latest and greatest when it comes to fishing electronics. thanks for any help

Both are Ethernet compatible.
Supposed to share GPS data and sonar IF the 1197 has the current software version. But some are not having any success doing it. Some even state they don't like the 2D sonar performance of the 1197 with current software.

Software version 6.640 or higher has to be on both units for them to "talk". The XX9 models started with a version higher than 7.000 so that makes it mandatory for the 1197 to have at least 6.640

Ethernet is the only connection you can use. Ethernet does not write the waypoints to the other unit's memory. It displays the other units waypoints in a different color.

The issue with sharing a transducer, is the one at the bow will be getting sonar data from the transom. Not very effective when using some presentations (vertical).

While you can adapt the SI transducer that comes with the 899 for trolling motor mounting, if you have a variable speed trolling motor, the likelihood of RFI is high. There is a trolling motor puck version of that transducer that has extra internal shielding (XTM 9 SI 180 T), or the same one you have with the 1197 (XHS 9 HDSI 180 T) that is more suitable for that application- just need a trolling motor mount for the HDSI.