i had no idea about free diving until i read the OP. Natalia, the subject, who was one of the handful of world elites, and had been for many years, had a couple

i had no idea about free diving until i read the OP. Natalia, the subject, who was one of the handful of world elites, and had been for many years, had a couple of years before (2013) descended to a depth of 418 feet, and ascended back to the surface under her own power--no supplemental oxygen, used at anytime. Absolutely amazing. I had no idea humans could do that--with or without training.