Honu-po'o-kea dug a shallow hole and laid an egg, as dark and smooth as polished kauila wood. Her mate, Honu-'ea, had been waiting offshore, his reddish-brown shell bobbing in the surf. As Honu-po'o-kea covered her nest, Honu-'ea joined her. Together the turtles dug into the black sand and created a spring. Then, as silently as they had come, they disappeared into the ocean.

In time, the egg hatched into a magical turtle named Kauila. Kauila made her home at the bottom of the freshwater spring that her parents had made. People called it Ka wai hu o Kauila, the rising water of Kauila. Children would come to play in the spring, and if they saw bubbles rising from its depths they knew that Kauila was sleeping. Sometimes Kauila would transform herself into a girl so that she could play among the keiki. Always, she kept a watchful eye on the children, insuring their safety.

Honu, or green sea turtles, still come to the black sands of Punalu'u on the Big Island. They can be seen grazing on seaweed in the surf or basking in the warm sun, oblivious to the people that gather to watch them. At night the rare honu 'ea, or hawksbill turtle, has been known to nest in the area, just as Honu-po'o-kea did so long ago.

Here and there the black sand bubbles as cool mountain water from Mauna Loa percolates through the porous lava. This was Kauila's gift: fresh water for the people of Punalu'u. Long ago Hawaiians would dive to the floor of the bay to collect the fresh water in gourds. Hence the name Punalu'u, which means diving spring.