What kind of details are you looking for? Land or over the lake? If its the former, then perhaps an Open Street Map basemap would work?

The harbor/marina details I'm interested in (piers, bridges, basin, docks, waterways, and hazards) would probably be considered land features.

Is there a way/procedure to combine a detailed land map (raster, satellite, OSM) with vector area/line/point features of the lake layered on top. I would like to avoid using shape files and associated attributes for all the land based features.

Usage is more restrictive when working with raster tiles. Refer to OSM's page on the usage policy: wiki.openstreetmap.org/wiki/Tile_usage_policy .

The IMC is capable of handling *.osm.pbf (preferred) and *.osm files as if they are vector shapefiles from download.geofabrik.de/ . The application will automatically assign all attribution for you.

I think I have so solution for your question. If i have a little bit time i will upload some pictures.

Background map (raster) = google earth
overlay (vector) = self made in RM => Points of interest like old tracks / lanes, big stones, areas with gravel, old buildings which are normally under water, etc.

Definitely give the OSM layer a go as well - perhaps take a look on an OSM map page first to see if they have the features you want. If it looks like it would be worth including, head over to the download page at Geofrabrik.com and download the smalled PBF file that you can find that covers your area of interest. You can then simply export your map from RM using the OSM background preset style, and specify your downloaded PBF file for inclusion. Note that this will take a while to generate, as there is a lot of data. Another way to do it is to generate your OSM map once in the IMC and then include this on your SD card in a sub-folder. You can then generate RM maps independently and store them elsewhere on the card - they should all load and display together.

Heiko's idea is also a good one - a satellite image background raster might show you the best level of detail, with your RM map on top. You might even be able to get this to play nicely with an OSM basemap, although it is possible that your area features (polygons) will be obscured by the raster.

Greg, you're saying, just add an *.osm file(s) to a vector mode project and IMC will automatically insert the osm objects as the bottom layer with approriate attributes.

Heiko, I would like to pursue this option also. Please point me in the right direction.

Matt, you're saying I can create two separate vector project at5 files, 1 with shapefiles, 1 with osm details, and my HDS unit will layer them correctly.

Since you are US based, you can also look into NAIP. Depending on the area, it's up to 1 meter resolution aerial imagery.

mabrykr wrote:
Not as the bottom layer. It assigns attribution to the OSM data objects and you can merge in your own data as you would with any other vector layer.

Greg, if the OSM objects have attributes like my shape files, what would the LAYER attribute be automatically set to?

It depends on the feature. There are a ton of objects that are represented inside an OSM file.

The OSM parsing logic is a few thousand lines of code so identifying how each feature is created isn't really feasible.

Ocean's (and anything that is generated through the parsing of a coastline feature), for example, are done as:

Layer 80
Lower Limit 0
Upper Limit 34
Fill Color 16
Border Color 9
MajCat "Nautical"
MinCat "Ocean/Sea"

Ok, I think I'm starting to understand the "Notes on OSM Conversion" paragraph in the IMC Documentation. If I use LAYER attribute 1-29 my shape files will be on top of all OSM layers. I could try to utilize OSM objects on top of my layers by using LAYER attribute 30-80. All OSM features excluding road names are automatically attributed by IMC feature parsing.

Seems like a lot of effort has gone in to this much appreciated product.

Instead of 30-80, it's 30-100. 80 is just the layer that oceans occur on.

Each type of feature also has it's own layering. All points appear over all lines which appear over all polygons. There's 1 exception: Drawing Objects which can be set to appear in the point layer.

Road names are assigned as attribution to the road but only road symbols are represented as their own graphical objects.