If you liked the Dwarven Forge "Watery Passage" tiles, you'll like these, designed heavily from images of their game tiles. Ive modified the color to fit my specific needs so that my floor colors match. The tile also has a three plane animated texture (all done with animesh).
http://imgur.com/Xrpk4Dp
I still need to fine tune the edges, but they look pretty good so far. So far there are 15 tiles, but some of the corners are interchangeable, so I can make more varieties from these by slicing and mixing them up.
In this image, you can see some of the higher poly contouring I'm working into all the tiles.
The lighter colored things are dogtooth calcite clusters growing under the water. Depending on the color of the water plane, you can see them better, or even tint them. The rest is a murky darkness which prevents you from telling how deep the water actually is. The raised section is all walkable out to the drop off. The step stone growths are to be re-textured to a lighter layered stone appearance, and possibly reduced in height. Right now they are 5 cm of the walk plane. I'm trying to find the right combination of height which still gives the impression of a raised area, without actually causing a visual clipping nightmare.
The animated water is a series of three planes, all set to "rotate texture" so they line up from tile to tile. The first plane is whatever color you want the water. Changing that texture changes everything. The next plane "up" is a simple ocean texture, which scrolls right over 4 seconds. The third plane is a copy of the previous but scrolls left. Changing the uvw rotation on the second moving water plane makes a world of difference. If they flow 15-45 degrees of each other, they look like flowing water. If they flow 180 to each other, they look like slightly wavy water in a light breeze. This is one of the water methods in Drakensang Online, and makes up a larger portion of the water in Sword Coast Legends.
By adding a color tint to the underwater crystal clusters, you can make quite a fantastic alien display. I originally modeled them in bright green, and that set against the darkness of the water depth was definitely something out of a fantasy world.