Responding to your questions about "how to show water" encouraged me to look at my art quilts from the last five years. Most of my art quilts are painted on whole cloth, then quilted and embellished. Here are my tips and techniques about HOW TO create the impression of water in art quilts: (Of course, other art quilters have a different tool box.)
A mass of French knots creates the impression of foaming water, especially around the hooves of the seahorse. (The whole image of "Emerging" is here. - The following examples have a link to the overall image as well.)
In "Water Wave" hand-spun wool and silk creates the dramatic curliness and change from thick to thin.
This art quilt also uses the Tying technique to create "silver rain".
This Sea Horse from the Roman Horses series mixes hand-spun yarn with French Knots. Large, uneven hand-quilted stitches symbolize the flow of water.
Same technique: The large, curvy, hand-quilted stitches show the currents of the Seine river - bottom panel of in "Found and Made in Paris."
Crouching of recycled nylon veil creates the bubbly surface of "Bubble Bath." Here with a sideways view:
The "Glass of Water" is painted, the outline hand-quilted and then the thread is pulled through the top level of stitches.
"Flooded Fields" uses a linear perspective with one vanishing point to create the illusion of depth. The water of the flooded field is mainly hand-stitched, with a little bit of machine-quilting in the foreground of this image.
"Donner Lake" shows machine-quilted reflections in the middle ground.
"Sailing Under the Golden Gate Bridge" is to-date my latest art quilt around the "water" theme. It uses several techniques:
Background: Machine-quilted reflections in the distance
Middle ground: Hand-quilted and embroidered with French knots that reflect the highlights of the waves.
Foreground: Hand-stitched big loops with lurex yarn to create the effect of white water under the leaning boat.
All-in-all, this art quilt is hand- and machine-quilted, and embellished by yarn appliqué.