[Tagging] [tagging] Canoe route / nautical channels

osm.tagging at thorsten.engler.id.au osm.tagging at thorsten.engler.id.au
Tue Jul 3 10:24:13 UTC 2018

> -----Original Message-----
> From: Christoph Hormann <osm at imagico.de>
> Sent: Tuesday, 3 July 2018 18:26
> To: Tag discussion, strategy and related tools
> <tagging at openstreetmap.org>
> Subject: Re: [Tagging] [tagging] Canoe route / nautical channels
> On Tuesday 03 July 2018, Multi Modaal wrote:
> > [...]
> >
> > Summary:
> > I would suggest using [waterway=canal] or [waterway=river] for
> > routable lines across bodies of water despite the fact that you
> > normally wouldn’t call them as such. This because of common current
> > practice for routable networks and other practical reasons.
> Note Multi Modaal is trying to push this idea of tagging for the
> router into the wiki as established use of waterway=canal (which is
> obviously not).  Here what i added there explaining why this is a
> very bad idea:
> Such use of waterway=canal is in fundamental conflict with the main
> purpose and primary use of the tag to map artificial physical
> waterways and is therefore strongly discouraged. It can primarily be
> considered Tagging for the renderer to place labels and tagging for
> the router.

Fully agree. 

waterway=canal or waterway=river are not appropriate for mapping either physically unmarked routes or routes marked with buoys inside larger bodies of water.

https://wiki.openstreetmap.org/wiki/Tag:waterway%3Dfairway does seem appropriate for the later. So that's basically the answer to the "nautical channels" thread.

A waterway=canal, waterway=river, or waterway=stream way inside a lake or pond is probably appropriate to connect an in-flow to an out-flow in a direct line, to allow software to easily trace waterways through lakes or ponds (which are essentially just widening of the waterway) without having to process areas. In this case the waterway going through the larger body of water should share a node with the outline of the lake at the in-flow and out-flow points where they way and the outline intersect.

> The commonly used method for mapping boat routes with regular service
> is route=ferry. Routes used casually, non-regularly and with wide
> variation in geometry by private boats are not verifiable and should
> therefore not be mapped in OSM.

Where you have a lake, and there are a pair of pretty clear points where it's possible to put your canoe (or similar sized boat) in or take it out of the water, I do think it's appropriate to connect these points with a route=canoe way if it is part of a route=canoe relation (which includes both water sections and sections on land).
So that's basically the answer to the "canoe route" thread.

> I hope there will be community consensus not to abuse waterway=canal
> or other waterway tags this way and we can remove the whole paragraph
> again.
> On a general note and as a suggestion to mappers who might be
> irritated about how to deal with OSMs free form tagging system:
> * inventing new tags so far not used and documented is fine - but you
> should document them.
> * adding new uses to secondary tags (like using surface=* or usage=*
> on features it is so far not commonly used on) is also fine if it
> matches previous use in meaning.
> * adding new uses to existing primary tags is highly sensitive and
> should usually be discussed first.  Creating a new tag is almost
> always a better idea.

I agree with all of that.

More information about the Tagging mailing list