Water Rim is a geometry node group for Blender from NENGHUO Studio. It generates tension lines at the contact surface where a water surface meets an object, and it can also generate foam. Both effects live inside Blender's geometry nodes system, so they fit into a node-based workflow.
The product ships with documentation, and a tutorial video is available to walk through its use. It works in Blender 4.1 and later, with listed support for versions 4.1, 4.2, and 4.3.
Water Rim is offered under a royalty-free license that covers personal, portfolio, and commercial use on the developer's page, and it is listed as free in this catalog. For current licensing and any setup details beyond the included documentation, the developer's page is the place to check.