What is the difference between OW and AOW certification?

Open Water certification is your entry-level scuba qualification. It teaches the basic skills of safe diving, such as gas management, buoyancy control, dive planning, and emergency response. Once certified, you can dive independently with a buddy to a maximum depth of 60 feet (18 meters). That certification is what allows you to rent tanks, join dive charters, and dive almost anywhere in the world.

Advanced Open Water, in my opinion, is one of the most misleading names in diving. There is nothing “advanced” about it, and earning the card does not make you an advanced diver. Because scuba training is self-policed by the agencies, they needed a way to separate very new divers from somewhat new divers, and that is what Open Water and Advanced Open Water really represent. You can literally become an “advanced” diver with as few as nine dives, four in Open Water and five more in the Advanced course. I even know of one agency that issues an Advanced Open Water equivalent certification without requiring any additional dives beyond the four open water training dives.

If your goal is to expand your depth limit or build real skill, take the Deep Diver course instead. Over time, as you complete five specialty courses beyond Open Water, you will legitimately earn the Advanced Open Water certification anyway. It will take longer and cost more, but you will actually learn something useful instead of skipping straight from beginner to a label that overpromises what it delivers.

Scuba Training Progression: What's Next After Open Water?

Newly certified diver? Learn what to do after, from gaining experience to choosing the right specialty classes. Hint: Skip Advanced Open Water.

Rescue Diver Course: What to Expect and Why It Matters

Learn what to expect from the Rescue Diver course, when to take it, and why it’s a pivotal step in becoming a safer, more team-focused scuba diver.