Have any of you looked at the lake mapping software available from Garmin and Hummingbird as a free feature on some of their GPS depth finders? Specifically, Garmin has Quickdraw Contours which maps your lake as you cruise the lake with 1 foot contours. Hummingbird has Auto Chart which does the same thing. From what I understand, these programs are very accurate providing great detail.

As a little background, my lake is 20 acres with probably 50-60% of the water 10 feet deep or more. The deepest area is about 26 feet. The lake was built in the 60's so there is very little visible cover but a lot of underwater stumps, bushes, and trees. I am looking to upgrade my depth finder to a Side View unit to help me identify deep water structure and cover. The idea of having mapping ability is intriguing. I don't know if it is worth the extra money though. Are any of you familiar with this technology?