You have no choice about mapping or not, they have ContourXD mapping built in. You can add Lakemaster and Navionics mapping.
Exchange the included transom DI transducer for the proper trolling motor puck that has extra internal shielding.
The XTM 9 DI 25 T is tuned to the same frequencies as the transom transducer.
The XTM 9 WIDE DI 20 T is tuned for 83/200 kHz 2D sonar.
You choose the 2D coverage you want.
Edited by Wayne P. (08/08/16 08:30 AM)
Humminbird Helix 12 CHIRP SI, 1198c SI, 1198c SI, ONIX 10 SI NT, Helix 7 CHIRP SI GPS G2, SOLIX 12 SI, 360, RC-1