Lets start with an example:

Now, how is it done? ... read on!

Step 1. Obtain raster charts from NOAA.
Raster charts are freely available on the NOAA website. Follow this link, -Chart Download- click on the chart you would like to have and scroll down in the right hand panel and choose "Download RNC". You will end up with a zip file named
.zip that contains a folder named BSB_ROOT. Inside BSB_ROOT will be one or more .KAP files. The .KAP files are the ones we will be converting.

Step 2. Obtain and setup the free, open source conversion software.
In windows, you will need to install osgeo4w (we will be using the gdal portion).
http://download.osgeo.org/osgeo4w/osgeo4w-setup.exe

Open osgeo4w-setup.exe and walk though the install process:
choose advanced install -> install from internet -> all users -> (use any directory you want) -> direct connection -> select the following options:
commandline utilities
gdal16, setup, shell
libs
gdal16-python, python-win32

Step 3. Convert your .KAP file to KML for Google Earth.
Open up the OSGeo4W command prompt and type the following command and hit enter:

Example:

Now type the following commands replacing <filename> with the name of the .KAP file and <newfilename> with any name you like.

Example:

You will end up with a directory called <newfilename>. Inside will be a doc.kml file that you can open with Google Earth. Here is the result:

I hope you enjoyed this, of course using the command line is not for everyone. So, if you don't want to do all the hard work, you can head over to EarthNC where you can purchase complete sets of both raster and vector charts for Google Earth.