[OSM-talk] Hot to build a marine chart for garmin devices?

[Christian Wagner]

Around January someone, I think it was Mark Burton, built a Garmin map
for the Openseamap guys. It covered the southern half of the Baltic Sea.
It had different symbol styles for all the seamarks (buoys etc.), a nice
white background for the sea and a light brown background for the land
areas. To me this map was perfect.

Unfortunately this map generated back then was the only one that used
this style. No updates, no documentation of how to built something like
that yourself- nothing.

Unfortunately the documentation of the mkgmap programm in the wiki is
far from useable to a newbie. All this about style files, options like
--generate-sea:multipolygon or --generate-sea:no mp - I don't even know
what all this is. Could anybody please point me in the right direction?
Is there a proper documentation of the files that I have overlooked?
The page http://wiki.openstreetmap.org/wiki/Mkgmap/help/usage seems
useless to someone who wants to render seamarks and have a white sea
polygon with brown land.

Let's say I downloades the OSM file of the area and I downloades mkgmap-
how would one proceed?

Thank you very much in advance and forgive my ignorance if I missed the
obvious,
Christian Wagner