I was looking into water lines to show large water bodies, usually on vintage maps. It looked like just a series of buffers. So I made a script to create them, it should be attached as a Python Toolbox. Written in ArcGIS Desktop 10.3, I am unsure if it causes issues in previous versions. The tool takes a source feature class, an output feature class name, the number of water lines to generate, a value for the closest water line, a value for the farthest water line, and the algorithm to determine the spacing (Linear, Log, Cosine, Geometric). It uses in_memory feature classes to speed up processing. Buffers that are far away from the input features take longer to generate. Simply run it to test how long it takes.