Shells, sea glass, pebbles, or other beach finds
1 (4.4-pound) box of plaster of Paris
Water (fresh or seawater)
Beach bucket or other container and a stick for mixing the plaster
Dig a flat shape in moist sand about 2 inches deep. While working and molding the sand, use a spray bottle to mist the sand so that the mold will hold its shape.
Arrange shells (facedown), sea glass, pebbles, and other beach finds in the mold to create interest or features. Gently press the items down to anchor them in the sand so they won't move when you add the plaster of Paris.
Mix some plaster, making it thick and creamy so it will not run under the items in your mold (we used 7 cups of plaster and about 3 cups of water). Very gently pour the plaster into the mold, filling it slightly more than halfway.
When the plaster has set up enough to hold together but is still not too firm (generally an hour), dig the sand away from the fish and gently brush away any flaws and excess sand. Handle it gingerly until completely cured (about 24 hours).