Professional rebreather diving instructor Jill Heinerth helps divers navigate the complex, and sometimes intimidating world of rebreather diving. Providing clear, candid and straightforward information based on her decades of exploration and teaching experience, Jill leads readers through the histor...

Having a safety back-up air supply has many advantages over a standard alternate air source. The most obvious is that it is a separate air supply and allows self rescue in an emergency out of air situation. We are taught to stay with our buddy so that in case of an emergency they are right there rea...