[RBEmerson]

Yep, just do an unzip. The files come in the form
/BSB_ROOT/nnnnn/nnnnn.bsb
and
/BSB_ROOT/nnnnn/nnnnn_x.kap
(where nnnnn is a chart number and x is a chart component sequence number)

When unpacking, specify a destination sub-directory (e.g., /home/gandalf/charts - substitute your real home sub-directory for "gandalf" - unless that's the name you use, too...) and the charts will unpack there. Look in /home/gandalf/charts/BSB_ROOT/ and you'll see a sub-directory for each chart you've downloaded.

Note: you can extract the files and strip off the sub-directory information, to make one "flat" sub-directory filled with all the .bsb and .kap files. If you're trying SeaClear II, for example, this is required. You can not do this with ENC files! (well, you can do it, but expect to see a lot of overwrites and lost data...)