Hi,
I created a testmap, which can be downloaded and tested with the Lowrance HDS units - Gen1 maybe with little limitations. The map also should work on the Elite 7 HDI and the new Elite 5 HDI units.
The included at5 vectormap is an at5 V10 and additionally should run on older units.
The lake consists of correct data, but I transferred it a few kilometers south of its original location. You could find the lake about 45 kilometers south-east from Munich, South-Germany.
http://www.coreboat.com/downloads/Testsee.zip
You can also find the coordinates on the screenshot.
The map consists of the raster map in higher resolution and the vector map with an included POI.