I have stayed out of this until I was a bit more sure what Roger was looking for. I use Offshore Navigator and EIC for the US, where I have all of the charts on my computer hard drive.
The problem is getting down load charts for the world--not just the US. There are a number of programs, and they all have some features which are good, but none which will do it all.
The NOAA charts (and some of the DMA) are free and distributed at low cost (such as the DVD from MapTech) or on the net free as EIN.
The British Admirality charts cover the world well, but there are very expensive if purchased on CD or DVD (Fugawi will read the Admirality charts) C Maps probably have the best chart ploter based series--but again very expensive. Navionics also has chart chips for the world--also expensive. Plus none of these are really accurate--there are too many discrepencies which have not been fixed.
"The Digital Nautical Charts: The Digital Nautical Chart® is produced by the National Geospatial-Intelligence Agency (NGA) and is an unclassified, vector-based, digital database containing maritime significant features essential for safe marine navigation:
http://www.nga.mil/portal/site/dnc/inde ... _door=true"
These files are read in Vector Product Format (VPF). ArcView 3.X is the current preferable VPF.
http://www.chersoft.co.uk/Resources/Che ... Vector.pdf Gives a good description of Vector vs Raster charts.
Chersoft and Eagleglobalsoft (coastal Navigator):
http://www.eagleglobesoftware.com/formatsrd/DNC.htm
Both make chart reading programs which will read the above, plus the DNC.
Fugawi program information is available at:
http://www.fugawi.com/web/products/products.htm Fugawi makes distributes US, Canadian, European and International charts on DVD. They also allow you to use Navionics chart chips, with a reader. This may be one of the better ways to go for world wide navigation--especially with RayMarine or Furuno chartplotter and a computer on the boat. It gets very expensive for the Navionics chips just to look at charts.
Finally Jeppesen now owns Nobeltec and with the latest edition of Admiral or Visual Navigation the ultra rich can buy the entire world portfolio of Passport charts:
http://www.nobeltec.com/products/pdf/WF ... Report.pdf
I suspect that this will set you back a few grand--maybe more!
Frankly, you can get a lot of information from Google Earth, unless you have to have depths and nav aids. The coastal photographs are quite good in many parts of the world--some are better resolution than others, But in clear waters you are able to give a fairly good estimate of the depth and the path into harbors. I just ran thru some harbors which I know well, and unless there happen to be clouds, and if the resolution is good, the resolution is almost unbelieverable--for example look at Cabo San Lucas--better than the chart!
If I wanted detail, I would spend some time with the NGA web site and down load these charts and play with them. It will probably take some time to get it all working, but that is what your military is using (the web version I suspect is "dumbed down a bit".