I recently bought a Lowrance Elite7 HDI and am looking to get a lake map chip for it. My question is which chip has the best coverage and detail of the lakes of Maine? Any help or recommendations would be great!

You can view the actual maps that Navionics has on their web site's Web App.

IF you are going to be in a particular region and want a preloaded chip go with the Navionics Hotmaps, if you travel wide or want the ability to select the areas you want on your chip the Navionics + chip will save you some bucks.