SDI Open Water Scuba Diver Practice Exam

Which method is commonly used for clearing water from a regulator second stage?

1. Exhaling into the second stage

2. Inhaling sharply

3. Swallowing water

4. Coughing into the regulator

The correct answer is: Exhaling into the second stage

Exhaling into the second stage of the regulator is the most effective method for clearing water that has entered the mouthpiece during a dive. This technique works because when a diver exhales, air is pushed out through the regulator and creates a pressure difference that forces any water out of the second stage and into the surrounding water. It’s a natural and intuitive action for divers, as they are already accustomed to using their breath to control the regulator's function. Inhaling sharply can result in the diver unintentionally drawing more water into the regulator, which is not ideal when trying to clear it. Swallowing water is not a practical solution while underwater, as it does not address the presence of water in the regulator and can lead to discomfort or choking. Coughing into the regulator is unnecessary and could create additional bubbles or discomfort, and it does not effectively remove water. Thus, exhaling into the second stage stands out as the correct approach to achieve quick and efficient clearing of water from the regulator.