<pulling out all...>
that could be my test yes. It is usefull for waterfalls or rivers within a group only and I dont know any way to create the same effect for the usual tileset system w/o using a very large group. You need to control the whole mesh that represents the river for a seamless flow... so No idea how you can achieve that one @sen, looking very good anyway:
Unless the edge2edge timing and mapping of the anim is *very* precise, and all tile anims start and run at the *exact* same rate... If so, then mapping the south edge of the first tile so it starts/ends at one frame before the north edge of matching tiles might work...
That is, have the map scaled so that the south/east edges overlap to the south and east by one anim frame's worth of distance - i.e. if you have a 1000 frame anim (a 33 second anim... should be about right for water, I'd think), then the water map needs to be 1cm bigger than the geometry it's mapped to. So you only see the first 999 frames worth on tile 1, the last/begining of the loop occurs on the next tile over.
<...his micrometers and sonic screwdrivers>