Making water with soft edge in Gimp

The first step is open GIMP and create a new image,with the brush tool, paint a blue patch that will serve as the basis for our tutorial.

http://www.cartographersguild.com/pi...&pictureid=469

Now we have this body of water, we can begin the work.
In the menu "filters" select "blur">"gaussian blur" the level it in this case is 70 pixels.

http://www.cartographersguild.com/pi...&pictureid=470

Use the menu "Colors"> "posterize" changed for 10 levels.

http://www.cartographersguild.com/pi...&pictureid=471

In the same menu "Colors"> "brightness-contrast" changed to 6 and 23 respectively.

http://www.cartographersguild.com/pi...&pictureid=472

Again use the "gaussian blur" filter this time for 12 pixels.

http://www.cartographersguild.com/pi...&pictureid=473

In the "layers window" create a new layer and add an "alpha channel" to it.

http://www.cartographersguild.com/pi...&pictureid=474

Paint or load a terrain to this new layer.
Now using the "eraser tool", erase the region over the water(in the new layer).

http://www.cartographersguild.com/pi...&pictureid=475

The end result of our work should be more or less like this:

http://www.cartographersguild.com/pi...&pictureid=476

Please feel welcome to correct any errors I have committed on this tutorial.

That's a nice looking water.

Lookin' good JP!