Scuba Diving International (SDI) AFS 270 Practice Test

Diving safety starts with the diver’s own awareness and ability to manage safety independently. Personal awareness means constantly evaluating your environment, conditions, and your own limits—watching gas supply, depth, time, currents, task load, and buddy status so you can spot risks before they escalate. Self-sufficiency means you have the skills, readiness, and mindset to handle common problems on your own or with minimal reliance on others—efficient buoyancy control, competent navigation, the ability to share air or execute an independent ascent if needed, and having the right contingency plans and gear redundancy.

Knowledge and training provide the methods you’ll use, and equipment and planning support safe dives, but they’re most effective when paired with a diver who is acutely aware and prepared to act. Physical fitness and discipline matter for safe performance, but they don’t inherently establish the safety approach the moment you begin a dive.