This site has the RNC (raster charts) in .bsb format.
http://www.charts.noaa.gov/RNCs/RNCs.shtml
This site offers software that can convert .BSB files to .tiff files.
http://libbsb.sourceforge.net/
I have graphic tools that will convert .tiff files to .bmp files.
Anyway, thought I would share this info.