One really great thing about living in Australia is its incredible coastline. After all, it is an island continent.
Coastal plants are sources of shelter and food for many animals. One significant tree is the palm. Many urban gardens have small palms growing that shed their fronds (leaves). The fronds get sent to the rubbish tip as garden waste however they may be an interesting resource for art projects.
In this case we are looking at the basic element - the base part of fallen fronds. They take on wonderful curving shapes not unlike the curve of a wave on the shore.
Consider if students will use garden tools or how they will be supervised by an adult
If you don't have easy access to palm fronds, why don't you think about how paper towel roll tubes might be able to turn into some raging surf?