From publisher blurb:
A glittering lake. Below darkly sylvan slopes its waters rise and fall restless, turned by currents of inscrutable caprice over unknown depths. From the canopy shading its shore rolls an even chug: the pumping.
Condensed to one page for slipping in among other materials, this sandbox-oriented content is intended as an easily absorbed framework for improvisation to be adapted by the user as preferred for a wider setting and specific system.
It presents core ideas and key numbers to fall back on, with general approaches that can be applied in other situations.
The content covers map generation on the fly for an abstracted lake as well as suggestions for aspects of the locality, including beings present, pumper activity, pulser-driven changes and caves in the walls.
Aspects of the waters and pulser behaviour could be detailed using Elaboration: Atmosphere & Liquid, while pumper devices might be developed using Being: More or Less Fantastical Olde Worlde Technologies.