Little nervous hands tug at the ruffles of a pink swimsuit as timid feet step onto the rough, wet surface and begin the long journey to the end of the diving board. Ominous shrieks and splashes echo around her as the cold air hits her skin, and she stops in her tracks. The edge is just five feet away.

“C’mon, Sarah-sweetie!” she hears her father call, his calm voice urging her mbele and rising above the noise that rings in her ears. “You can do it! Just a few zaidi steps and then you’ll see me.”

The little girl whimpers and wraps miserable arms around her shivering self. Her legs...