ZeroLine Map Card vs Lake Master Map Card

I am a new HELIX 9 MEGA SI GPS G2N user and new AutoChart Pro user. I am genuinely struggling. The ZeroLine Map Card came with AutoChart Pro. Question: Do I need a Lake Master map card, too? For some background: I fish and am mapping a 6+ acre strip mine and now that I have been recording with the ZeroLine Map Card, I have had blow in of contours to surrounding land from the first map I made in AutoChart Live BEFORE I had AutoChart Pro. The shoreline on the ZeroLine Map Card is too small so I am missing a lot of shallow water where the bass will be moving to and from. Thanks for any help you can offer. That is why I wonder if the Lake Master card has more detail for me and the lake in question.