I know the guys that do use them seem to really like them. I've heard the Lowrance Ice conversion kit for their color sonar/GPs units is much better then the Cabelas's kit, they sell for around $200 which is a little spendy. You may be able to rig something up a little cheaper.
Three-fourths of the Earth's surface is water, and one-fourth is land. It is quite clear that the good Lord intended us to spend triple the amount of time fishing as taking care of the lawn. ~ Chuck Clark