Tony I now have the Garmin 178C that one of my customers bought me for the boat. I love it and I just took the chip we use in the 176 you and I both have and put it in the 178C $$$ saved. They had them at the boat show for 650.00? One of my customers was there Fri and showed me he had bought one. Now if your 178C was to go down you take the chip out and go back to the 176, no down time and Garmin is great about repairs from what I have seen. I also did have the 240 blue Garmin ff so I did not even change the transducer so I now have a spare. Also kept the 240 so if there shuold be a problem it goes right back into service. I think it would be the way to go for you to as if the unit did go down you would still have the GPS back up!!!!!!!!
Ps if you would like to try the 178C out I have it in the house and use it off of a back up charger unit with a cig. light plug. Come over any time and you can check it out. I think you would like it as much as I do. I also went with the internal ant. for easy hook up and use on the Quad also
