Step 1: Practice breathing correctly for several times - Get into a relaxed position before going underwater. Relax your body while sitting or standing in the shallow end of the water or on your boat.
Step 2: Dive slowly below the surface. Take a deep breath through your snorkel before you dive slowly below the surface. Again, stay relaxed.
Step 3: Once you’ve reached your body’s limit, resurface slowly and calmly. Before diving again, take another two or more minutes to do breath cycles and get your body back to its normal oxygen levels. If your dives are too close together you could suffer from a blackout due to lack of oxygen, so always stay relaxed and ensure you maintain high oxygen levels in your blood.
Step 4: Slowly add movements once you feel comfortable and avoid exerting too much effort as it will use up more oxygen.