"Imagine your lungs as a miniature BCD," she wrote on the board. "Take a deep breath; your body will rise slightly like a balloon."
"Slowly exhale all the air in your lungs; your body will sink slowly like a stone. Find the critical point that's just right, and you'll be able to float like a feather in the water."
For Lin Yu'an, it was a challenge tailor-made for him. His extraordinary body control and perception were fully displayed at this moment.
After just a few attempts, he found the feeling.
He closed his eyes, no longer thinking about the operation of the BCD, and focused all his attention on his breathing and the subtle rise and fall of his body in the water.
He could clearly perceive how much his body would rise with half a breath and how much it would sink after exhaling a third.
Five minutes later, when Riven looked at him again, she saw a scene that she would never forget, a scene that was somewhat beyond belief.
