FineScale has done several articles on it:
Spring 1982 - Waterlining
Feb 1984 - Modeling water with Artist's Acrylic Gel
June 1987 - Modeling Water from Above and Below
May 1990 - Modeling Water with Acrylic Resins
Sep 1996 - Land and Sea with Sculpey
Dec 1996 - Making Water the Easy Way - Painting
Maybe you can get your hands on one of these.