An advanced open water certification allows you to dive to depths up to 30 meters. To become a certified advanced open water diver from PADI you need to complete a deep water dive and master underwater navigation. In addition you must complete at least three specialized dives from the 15 available adventure dives offered by PADI.
Deep water diving requires that you learn the specifics related to diving in depths of 18 to 40 meters, special considerations that need to be taken into account when diving to deeper depths and how to accurately organize and plan timing for deep diving. This includes timing for safety stops and surface intervals to ensure you are diving in a manner that will not harm your health. You will make at least four deep dives under the supervision of your PADI Instructor.
For your underwater navigation dive you will need to proficient in navigation patters, navigating without a compass, compass navigation, underwater map making, dive site relocation, estimating distances underwater and how to locate and object or position from the surface of the water. You will also need to complete a course navigation underwater with the Nav-Finder.