In the past few months a lot of public tile servers have started to block access from apps such as Mobile Atlas Creator as these bulk downloads were putting to much of a load on the servers.
A minority of users spoiling things for the majority!
If you didn't require the OpenSeaMap tiles and was happy to use the standard OpenStreetMap style tiles then a solution would be to set up your own tile server.
Have a read of this thread:
http://www.b4x.com/forum/basic4andr...ughts-offline-maps-large-area.html#post129675
The instructions on the switch2osm website no longer work, sometime in the past month or so the location of two shape files that the package installer requests has changed.
Without those two shape files the entire tile rendering process fails.
If you wanted to set up a tile server you could follow those instructions and i could then let you know how to manually download the missing shape files and extract them to the correct location.
I also have a fully working tile server created as above which is a
VMWare virtual machine.
I have it as a compressed RAR file of just over 2GBs - with the help of snail mail i could let you have a copy.
With that working you'd then download raw OpenStreetMap data from
GEOFABRIK Downloadbereich, you'd need the raw data for the area you wish to create tiles for.
(The raw data for the entire planet can also be downloaded as massive ~17GB compressed database by the way).
You import that data into the tileserver database and then you can add your tile server to your Mobile Atlas Creator as a custom tile server and download as many tiles as you want.
You now have tiles with the default Mapnik/OpenStreetMap style - none of the extra features found on OpenSeaMap would be rendered on these tiles.
Have a read of this thread:
android - is it possible to download planet files of OpenSeaMap data? - GIS
That says that the osm data contains the data for the features that you want but the tile server, by default, does not render these features on to tiles - it ignores these features.
So if you have time to learn about
Mapnik, and how it renders tiles based on render themes.
And then have time to learn how to create your own render theme for your own tile server you'd finally be able to render the exact tiles you want - and be able to render as many as you want.
Problem #1 would be the amount of time it'd take to learn and create your own render theme.
EDIT: I wonder if OpenSeaMap would share their render theme with you if you asked...?
Problem #2 would be the size of the offline tile archive you want to store on the android device - tiles for the entire planet would take up many GBs.
The more zoom levels you include the larger the tile archive would be.
The tile archive would reach a point where it is too large to be used - OSMDroid just wouldn't be able to open a massive tile archive and extract the required tiles from it or wouldn't be able to do so in a reasonable amount of time.
Problem #3 is the sheer amount of processing required to import a large amount of osm data into the tileserver database.
The entire planet data needs over 300GBs of temporary disk space and a similar amount of disk space for the database.
You'd need a computer with as much memory as possble and as many CPU cores as possible.
And even then your entire planet import could takes days.
It might even run for 2 or 3 days then crash with an obscure error - and you can start again if you think it's worth the gamble!
(Small/medium sized amounts of osm data can be imported on a decent spec desktop PC).
Small tile archives which represent smaller areas of the planet are workable, and if you can handle the default
OpenStreetMap style of the tiles rendered by the tile server then you have a working solution.
And if OpenSeaMap were share their render theme you'd have everything you need!
Martin.
