I’m on a mission after my first two basic scuba diving sessions! I want to understand the nuances of the sport, improve my swimming every summer, and complete a seven-day course before I turn forty.

Rebreathers could make an ocean explorer’s ultimate fantasies come true. Recirculating the same air again and again might sound like science fiction, but compared against traditional scuba equipment, ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. WHEN POPULAR SCIENCE associate editor Herb Pfister offered up ...