Navionics Shaded Relief question

[TNReb]

I picked up the Hotmaps Platinum card. Using Chart Installer, I downloaded the shaded relief for one lake. No problem.

When I went back to download another lake, it warms me that it will overwrite the overlays that are already on the card.

Is there another a way to drag/highlight multiple lakes? I fish multiple lakes within a couple hours every direction. I'm not sure the Lowrance unit is going to handle the shading for an entire couple of states all at once. On the other hand, I don't want to have to remember to update my card every time I go fish a different lake.

[DR. DROP]

I have the shaded relief overlay downloaded for about 4 lakes up to 3 hrs from my home lake.
Just takes a longer download time.
Has worked good.

[TNReb]

I have the shaded relief overlay downloaded for about 4 lakes up to 3 hrs from my home lake.
Just takes a longer download time.
Has worked good.

When you say you have it downloaded for 4 lakes, did you just draw one big square around the entire area in the Chart Installer app?

[DR. DROP]

Yes sir.
Check this out. Helped me.