Final answer:
The 'Smooth the Sand' activity aids students in developing the sculling motion for swimming, which is essential for propulsion, balance, and direction in the water.
Step-by-step explanation:
The "Smooth the Sand" activity is designed to help students develop the sculling motion needed for swimming. Sculling is the back-and-forth movement of the hands that generates propulsion in the water, and is vital for maintaining balance and direction while swimming. This activity, which simulates smoothing sand with the hands, allows students to get a feel for the proper movement required in water activities like swimming where such skills are necessary.