At this stage you can admire your handywork in the emulator so SAVE AS LakeName.mp (dont overwrite the shoreline file so give it a different name), THEN export as shapefile.
Make sure that you load the 3 shapefiles that GME just created (points, lines and polygons) into IMC, and hit "build".
If you have your build location set as an emulator then remember that IMC creates a folder called BoundAT5s in the selected folder, so you will need to move the AT5 file down into the Maps0 folder.
You should now be able to open your emulator, and go find your chart. The first time it wont be immediately there on the screen - you'll have to pan across to it so make sure you have a position for it from GME .
It will look something like this. Right now we have no water background, thats coming soon, we need to deal with the islands next.