It's the correct tile type, but for Moscovia the puddle of water there is recognized as "not deep enough to count" similar to how you can't use waterball when the water barely scratched your feet in the graphics.
Potentially it may be because it's what the map-editor like to call "high number water" (I think Moscovia's muddy water tile is a 7 or something?) and waterball only works with the traditional "blue water". I don't really know heh... but the point is: lava is actually a type of water for the RO map editor, and a GM needs to warp on those illegal magma dungeon tiles to see if they can waterball on lava or not, since lava is also a "high number water" tile ._.;
For byalan, it's actually a "no water map" covered under a giant blue flashlight to dye the grey map a blue color, lol.
