I have always used Navionics map cards to help me locate certain contours, points etc while on the lake or prefishing for a tournament. I found on several lakes the Navionics card to be lacking in detail or it was inaccurate.

When I purchased my Lowrance HDS units I found a much better mapping system with more detail and other great goodies like vegetation and hardness of the bottom.  The cool thing about it is you can create the insight genesis map with your lowrance unit while fishing or just taking a drive on the lake. It's simple to do.

 

With it I have found areas on my lakes in North Idaho and Washington that I never knew were there. Or I created a map where there wasn't one. See the images below of what the Navionics card had available for this lake and then the maps I created in less 30 minutes with so much detail I don't only see the 1' contours but also every depression, humps, points and ledges including the hardness of the bottom in the one picture. Information I need to locate the smallmouth I am trying to catch.

 

This is a game changer.

 

 

Without doubt the very best and easiest surveying method around! Just a few simple steps to creating a very accurate chart.

One thing I would add to the proceedure is to add the ALTITUDE to your page Data Overlay and take a screen shot right after you launch. This way you have the most accurate offset when you upload your trips.

I love IG. The vegetation option is also helpful.

Navionics Sonar Charts Live and Humminbird Auto Charts Live does the contours as you navigate.  

 

This is Auto Charts Live overlayed on Sonar Charts:

 

 

With Lowrance GoFree, you can do Sonar Charts live to a mobile device.