WATER MASK / Educational Instrument

As a child, I had volunteered in the slums. The only play for them was to play in the water. However, because the children of the slums were not able to swim well, there would be a situation where they would learn to swim with their lives. However, this problem can be solved with minimal cost. In order to protect against water, you can put water in the opposite mask and use it as a swimming lesson.
Depending on how you turn your head, the height of the water is different, so you can teach about breathing outside the water.