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#1 2018-02-19 09:01:49

damianham
Member
Registered: 2018-02-11
Posts: 3

Downloads for seaways and coasts

I have been looking at various ways to download OSM data to populate a postgis db for a local tile server for offshore use.  As a sailor I am principally interested in the areas of water up to the coast and the seamarks.  If I just import the seamarks world.osm I don't get any coastlines or background water.  So I can also import the OSM data for GB from geofabrik for example to get the land areas however I have no need for the data for the hinterland - although a few miles of coastal land may be useful and town/city points.

The downloaded file sizes are approx world.osm (244MB) + GB.pbf (992MB).  I may never venture outside the UK in my boat so I have no need for seamarks beyond my cruising region.  My point is that the data I really need (seamarks for the UK + coastal land areas) would be minimal compared to the 1.2 GB of combined data from these 2 files.

It would be great if we could have some downloads of seas and their bordering land areas so I can just insert the seaways that I want to navigate.  At the moment if I run the download on a laptop with 4GB memory then the database insert is fairly quick but on a 1GB memory raspberry Pi I am expecting it to take a really long time.  I tried it on a 1GB virtual machine and it did take a long time!!!

What we need to do collectively to provide OSM downloads of seamarks for seas and streetmap data for their coastal land areas rather than individual countries ?

best regards
damian

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#2 2018-02-19 09:16:11

malcolmh
Member
From: Hull, UK
Registered: 2012-09-05
Posts: 177

Re: Downloads for seaways and coasts


Malcolm Herring, Developer

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#3 2018-02-19 11:28:41

damianham
Member
Registered: 2018-02-11
Posts: 3

Re: Downloads for seaways and coasts

Thanks Malcolm I did look at that website but I understood the data to mean it was land areas or water areas using the coastline tag to create the polygons.  I therefore assume there is no data about coastal land areas coastal roads, harbours etc. nor does it include town points and they are still 500MB for either the land or water polygons for the whole world.

Basically my point is that data for a limited coastal region might be more useful and easier to import and use than data for the whole world.  I understand that with osmium we can specify a polygon to select data within the polygon so a command like

osmium extract -p baltic.geojson europe-latest.osm.pbf -o baltic.pbf

would be very useful for a sailor in the baltic if a polygon existed to define the area for the baltic and it included coastal land areas e.g. 5 miles

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#4 2018-05-14 16:08:45

kannix
Member
From: Ruhrgebiet
Registered: 2013-10-27
Posts: 117
Website

Re: Downloads for seaways and coasts


Navigable Inland Waterways
http://maps.grade.de/

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