Diving Equipment Review: Spare Air Kit I watched a diver panic at 65 feet last year. His primary reg failed, his buddy was twenty feet above him, and he had no redundant air source. He made it to the surface—barely—but that bolting ascent could have easily ended in DCI or worse. That incident sits with me because it was preventable. Whether you need a redundant air source like Spare Air comes down to your diving profile, your risk tolerance, and how honest you are about worst-case scenarios. After testing five different emergency air systems across cold water wreck dives, warm water reef drifts, and confined overhead environments, I can tell you this: a diving equipment review spare air kit isn't about finding the "best" device—it's about matching the right redundancy system to your specific use case, understanding its severe limitations, and ne ...