[OSM-talk] 12nm territorial borders - useful or rubbish?

[Frederik Ramm]

Dave,

On 02/14/11 07:52, David Murn wrote:
> Im sure I remember reading a linked news story posted on this mailing
> list about a soldier crossing into enemy country because of incorrect
> mapping on his GPS.

In that case, should we perhaps deviate from our usual mode of operation 
("anyone can add anything even if it's only half-right and others may 
fix it later") to one where we only explicitly add territorial water 
boundaries where we know (or at least strongly believe) them to be where 
we add them - rather than adding an auto-generated 12nm line around any 
piece of coastline and leave it to the soldiers of this world to find 
out the details ;)?

> What happens if the international waters stretch further than 12nm in
> some areas?  The generally accepted rule is that 12nm is the edge of
> territorial waters, but by treaty/agreement this can be changed.

Maybe then we should only add this data where it has been changed by 
treaty/agreement? Much as most people don't bother adding maxspeed tags 
to every inner-city road, assuming that it is enough to put them where 
the speed limit deviates from the norm?

> A ships captain might look at a neatly laid out park and say 'why bother
> putting each tree, thats just showing off that you can make pretty
> patterns', in the same way that a non boating person might fail to see
> the value in territorial water boundaries.

My assumption - and I'm not a boating person so I may be wrong - is that 
if you're out on a boat with any working kind of navigation, you will 
know where the coastline is, and therefore you will automatically know 
where the 12nm boundary is - so having an explicit line would really 
only make sense where it deviates.

I doubt that whoever put the current auto-generated boundaries in has 
actually checked whether these are overridden by any treaties. (But I've 
emailed Roland who is responsible for at least some of them and alerted 
him to this discussion.) I have the suspicion that these lines in OSM 
mean "this is a buffer of 12nm around the coast which may or may not a 
territorial water boundary", rather than "this is a territorial water 
boundary".

Bye
Frederik