Adding OpenSeaMap to osgEarth

The following earth file loads OpenSeaMap tiles:

<map name="OpenSeaMap" type="geocentric" version="2">
    <image name="osm_mapnik" driver="xyz">
        <url>http://[abc].tile.openstreetmap.org/{z}/{x}/{y}.png</url>
        <profile>spherical-mercator</profile>
        <cache_policy usage="none"/>
    </image>

    <image name="sea_mapnik" driver="xyz">
        <url>http://t1.openseamap.org/seamark/{z}/{x}/{y}.png</url>
        <profile>spherical-mercator</profile>
        <cache_policy usage="none"/>
    </image>
</map>

The following is a screenshot when using the above earth file:



You need the combination of OpenStreetMap and OpenSeaMap because the sea features will only kick in around zoom level 8.