Use
This is an easy craft with a sophisticated look. It depends on how crafty you are!

Materials: Construction paper
Tissue paper
Chenille Stems
Elmer's Glue-all

Method:
1) Cut sea shapes from construction paper. You can do fish of various colors and sizes, shells, and starfish. Anything that has to do with the sea. Glue them on your piece of construction paper. When I worked with a group of young kids, age 5, I let them draw their fish instead of cutting them out.
2) Tear various colors of green and blue tissue paper into seaweed like strips.
3) Glue the seaweed into place. Make some of it come from the bottom of the page, but remember that seaweed waves in the current and some of your strips should go sideways.
4) Add the chenille stems. I chose to use 3, for economy's sake, but any number could be used. They are meant to stand for reeds and so the bottom should be glued and the top crumpled a little and left free to move with the current.