Jack Erbes wrote:
Josce wrote:
I am thinking of writing my own navigation software.
Not to save money, but just for the fun of it, and
because I would like it to be an "open system" so that
I can easily add features to it from time to time.
I have sorted out the hardware but I am having problems with
the electronic charts. The charts I would need right now
have to cover the Baltic sea.

When trying to find documentation about the "S-57" format
I only find very "strange" documentation which is not
very helpful. It is as if someone has made it obscure on
purpose?

It all seems to fall under the IHO international consortium:

http://www.iho.shom.fr/

Maybe in their efforts to keep everyone happy they have rendered it
incomprehensible? At any rate, there are many links about ECS/ECDIS
to pursue in many languages from he

http://www.iho.shom.fr/ECDIS/introduction.htm

It is very likely that I just haven't found the right
documentation for this, but the ones I have found like:

IHO TRANSFER STANDARD
for
DIGITAL HYDROGRAPHIC DATA
Edition 3.1 - November 2000
Special Publication No. 57

are not very intuitive, compared to nearly any Internet RFC, which
you just read and then start implementing it ...

Are there any commercially available charts that can be used on a PC.
And to make it clear, I have no intention of cracking any codes and
I am more than happy to pay for these charts and "lock" them to the
computer that I install them on.

I can't help you with the Baltic region. If it is of any help, for
U.S.waters the S-57 format charts are available for download for free.
The agency that manages that is the NOAA and they call the charts
Electronic Navigation Charts or ENC. You can read more about them and
download them from these links:

http://chartmaker.ncd.noaa.gov/mcd/enc/resource.htm
http://chartmaker.ncd.noaa.gov/mcd/enc/download.htm

And how do you read these charts?

The first link above has some links to chart viewers for the ENC
charts, and there are a number of commercial navigation applications
that will also use them. If you want to see a good example of a
navigation application that will use them, try the trial version of
Coastal Explorer:

http://rosepointnav.com/CoastalExplorer/NewCharts.htm

As far as I know, while there are several commercial products that
will use the S-57 charts, there not yet any navigation programs in
the public domain that use them.

Jack

I gather the OP wants to do it the hard way, hence his insistence on
ignoring all the excellent commercial software available at the present
time.

Whilst admitting that some of this software costs money, I don't think this
is the OP's reason for wanting to "go it alone".

Me? I enjoy sailing too much to spend hours re-inventing the wheel! Oh, and
I do have charts of the Baltic, I just don't sail there!


Dennis.