US Water BSB charts now free (NOAA RNCs)
 

NOAA has now made all US coastal water charts free in BSB format. They
are called NOAA RNC charts and can be downloaded from he
http://nauticalcharts.noaa.gov/mcd/Raster/index.htm

Fugawi has a free demo software (Fugawi Marine ENC), which reads the
charts and can be downloaded he
http://www.fugawi.com/demo/version4.html