[OSM-newbies] Estuaries and large bays

[Aspen Swartz]

I'm pretty ignorant about this but given this conflict it seems to me the
best solution is to tag the coastline of the bay natural=coastline and have
it be part of a polygon whose way is tagged with a subsidiary tag- not
natural=coastline but name=Bay of Thisname, because a bay is a type of
coastline- it's sort of subsidiary.  But you can't have a way whose only tag
is its name, can you? (the line from point to point across the sea side of
the bay) Don't you have to have a tag that indicates what sort of thing it
is?

It seems like openstreetmap is a little short on common nautical features-
like shoals, sandbars, reefs, lagoons, currents, shipping lanes.  Etc. These
things seem analagous to me to landuse, but they don't seem very explored in
OSM.  There appears to be an openseamap project in OSM, but with shipping
lane not being a tag, it can't be very well developed.  Reef is only a
proposed tag an the definition doesn't fit my understanding of a reef, for
example.

In my opinion the renderer should treat bays as something to label but not
mark out in a different color- they are something like a mountain range,
valley, or plateau- they are important features but drawing a crisp line
where they start and stop would be silly.   (Outlining them in the data is
not silly. Rendering the outline would be silly).   I see there is an
abandoned effort to work on these sorts of features at
http://wiki.openstreetmap.org/wiki/Proposed_features/Extended_place_tags.

The more I think about this the more complicated the details are.  No wonder
it isn't well worked-out.

Aspen
(Eulochon)



On Sat, Oct 23, 2010 at 3:11 PM, Andrew Harvey <andrew.harvey4 at gmail.com>wrote:

> On Sun, Oct 24, 2010 at 5:55 AM, swanilli <swanilli at gmail.com> wrote:
> > On 20/10/2010, Richard Weait <richard at weait.com> wrote:
> >> There are almost 15000 points in the OSM database that include
> >> natural=bay. There are 241 polygons that include natural=bay.
> >>
> >> Place a point in the bay, and tag it as
> >> natural=bay
> >> name=My Bay Name
> >
> > Given that for the entire coastline of the world there are only 241
> > polygons tagged natural=bay I would have to say that tagging a polygon
> > as natural=bay is extremely rare.
> >
> > I am in Sydney, Australia and there would be close to this number of
> > named bays within 100 km of Sydney alone. Tagging them as points and
> > not polygons is consistent with usage on official maps, simple and
> > avoids the problem of undefined boundaries at interfaces with other
> > bodies of water like oceans.
>
> Well I disagree there, so I would like to hear other peoples thoughts on
> this.
>
> I disagree because,
> * The wiki lists natural=bay as appliciable to ways
> * a Bay as defined by the wiki "is an area of water", not a point in
> the middle of a body of water.
> * mapped as way allows renderers to for instance render names for
> large bays at low zooms, and not render names for small bays untill
> very high zooms.
> * mapped as a way allows for someone to use the database to ask "Am I
> in ... Bay?"
> * yes, some or most of the time it is hard to find the exact sea side
> boundary of the bay, I don't thing that should be a reason for not
> using a roughly placed a way in lure of some "official" extent.
>
> > Given the problem of rendering polygons as natural=bay and the
> > rareness of this I think that Richard Weait's tagging should be used
> > and the tagging of polygons as natural=bay should be deprecated.
> >
> > If the body of water requires a polygon and tagging, then it should be
> > tagged natural=water, which does not have these problems.
>
> Don't map for the renderer
>
> http://wiki.openstreetmap.org/wiki/Good_practice#Don.27t_map_for_the_renderer
> .
> That said, if other people agree that a large area which is named "...
> Bay", should have the tag natural=bay rather than natural=water, it
> shouldn't be too hard for renders to start rendering bays the same as
> natural=water.
>
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