In Maps/_Tex/water/animated/ reside 16 textures named waternoise00caustig.tga through waternoise15caustic.tga, of size 256x256 pixels. They are animated so as to represent light refracted onto the bottom by waves. I find the scale of the pattern to be rather large. I just made up a version that has the scale of the pattern reduced to half, thereby making the pattern more 'detailed'. This was done by simply making a 2x2 mosaic of the same texture, they being already seamless. Then I reduced this mosaic back to the same 256 pixel square as for the original. This was repeated for all 16 textures. The result is better, I feel, being closer to the scale of the waves moving above.
In the 4-panel image below, the upper left is the old stock appearance, at upper right is the current stock version (in B.A.T., at least), at lower left is my own first version, and at lower right is the more detailed version I just cooked up.
Here's a snapshot of the new more 'detailed' texture in use. The location is Tulagi, on Squashman's Solomons map (for which I've done some other retexturing).