As you know, most countries in OGF have maritime boundaries, but they are not consistent with tagging. There are typically 4 variants:
However, according to OSM standards, I propose that we all start to use this one:
boundary=administrative, admin_level=2, maritime=yes and border_type=territorial.
This will be very useful for consistency, and it also prevents the maritime boundaries from rendering at low zoom levels (which makes the map clearer and better-looking).
Comment from mstr on 9 March 2019 at 14:52
What is the advantage of “border_type=territorial”?
It is rarely used so far and it seems to make the maritime boundaries not disapprearing? The maritime boundaries of Mergany (maritime=yes) disappear at zoom level 3.
Comment from tule00 on 9 March 2019 at 15:30
The purpose of that tag is to distinguish it from other maritime boundaries. We don’t have those right now, but I think it would be useful for consistency.
I think they do not affect the map in any way.
Comment from Luciano on 9 March 2019 at 18:13
My current standard is NO TAGGING on the boundary ways.
If the boundary is set up correctly in the relation, it should inherit its properties from the relation, which will drive the render. Adding tagging to the ways doesn’t influence the render in any useful way and just clogs up the database with unnecessary tagging.
Comment from tule00 on 9 March 2019 at 18:45
I’d have to disagree. When it comes to internal subnational boundaries, it’s understandable. Perhaps for national boundaries too. But for maritime boundaries I think it’s necessary to make the distinction.
Comment from Luciano on 9 March 2019 at 18:54
It rather seems to tag the utterly obvious. If you’ve done the nearby coastline correctly, and you’ve done the boundary relations correctly, then, “Oh, look, that boundary is in the water. I bet it’s maritime.”
Comment from tule00 on 9 March 2019 at 19:09
But maritime boundaries are not even rendered the same as land borders. They are supposed to be rendered only at higher zoom levels, because they don’t represent the actual territory of the country. I think adding a few extra tags to the boundary ways won’t cost the database much, yet it will very much unclog the rendering of the map.
Comment from mstr on 9 March 2019 at 19:29
It should be only “maritime=yes”.
“border_type=territorial” seems to hinder the disappearance of maritime borders at low zoom levels, doesn’t it?
Comment from tule00 on 9 March 2019 at 20:29
I don’t know. on OSM it doesn’t.
Comment from thilo on 9 March 2019 at 20:31
Seconding the use of “maritime=yes”. As mstr said, this is indeed what determines which boundaries to draw at zoom levels 0-3.
Comment from Luciano on 9 March 2019 at 20:33
@Thilo. Aha! Then I was wrong. If it affects the render, then it serves a purpose. I’ll be sure to add it. Thanks for adding your comment.
Comment from tule00 on 9 March 2019 at 20:35
That’s what I meant to say. If the render were the same, I wouldn’t make such a big deal. But in this case it matters.
Comment from tule00 on 9 March 2019 at 20:36
Come to think of it, the border_type key is not crucial, but it would be useful for consistency.
Comment from Ūdilugbulgidħū on 10 March 2019 at 18:16
This was really confusing me as I’d set all my boundaries to maritime=yes a while ago, but they were still showing up on zooms 0-3. Looks like a render update has sorted it out just now.