Stretched Mask.

When you pan a warped texture, it can be annoying to see the patterns repeated too often.

If you're going to pan it only or mostly in one axis, what you can do is create a long rectangular texture and use a small tiling value on the long axis in your material (0.1 in the example below). As you create the texture, you need to keep in mind the ratio it will be used at.

The top texture is the original with unmodified UVs.

 

You could for instance use this method to create a wobbly mask that will bring an illusion of flowing liquid.