The figures showing the geographic location of seas and their bathymetry were created using the GMT graphics package along with the ETOPO5 data set for bathymetry. The GMT package contains a shoreline, lake, river and political boundary database that is a highly processed combination of the World Data Bank II (WDB, also known as the CIA Data Bank) and the World Vector Shoreline (WVS) databases. This database is actually a set of five databases ranging from one with only coarse detail to one with the full available resolution, allowing a similar level of coastline detail to be plotted for graphs ranging from views of the entire world down to plots no more than 20 minutes of longitude wide.
The ETOPO5 database contains a 5 minute grid of land elevations and ocean depths for the entire globe. NOAA's National Geophysical Data Center has a searchable online ETOPO5 database that allows the interactive selection of subregions via specification of latititude and longitude boundaries or by specifying a region on a selection map. This creates a file in either ASCII or binary format that can be downloaded via FTP for further use.
The land/ocean water boundaries are plotted by a call to the GMT program pscoast with the appropriate parameters. The downloaded ETOPO5 ASCII file is then transformed into a NetCDF format file amenable to use by GMT with the xyz2grd program. The bathymetry contours are then plotted using this file and the pscontour program. Finally, place names are added to the map using the pstext program.
The final result of running all of these programs in a single job script file is a file containing PostScript source code for the desired graph. This is fine for the hardcopy version of the glossary (although I'm not quite sure yet as to whether these will be embedded in the glossary or available separately), but a GIF format version needs to be created for the online version. This is accomplished using a Perl script called pstogif that is included in the LaTeX2HTML package. This calls several programs in the NetPBM package to transform a PostScript image into a GIF image and, as an added bonus, creates a GIF image that is on the order of 20 or so times smaller than the original PostScript.