Fill the bottle with water, pop in the two glass vials with lids, (put them
in "upside down" with the lids on the bottom), and screw on the bottle cap.
Squeeze the bottle and observe what the glass vials do.
Observe the system carefully. Note what is happening inside the vials.
Put a few paper clips inside the vial. How does this change its
performance as a diver?
Check the box when you are done: