I've decided to give up breathing air. It gives me a headache, induces an itchy, dry throat and leaves me exhausted. From now on I will only breathe enriched air, commonly known as nitrox. This gas ...

Jaquan Greene buckled the scuba vest, adjusted his goggles and stuck the regulator — the device that delivered air from the gas tank strapped to his back — into his mouth. He listened to Kim Walker, a ...