What is the primary purpose of exhaling deeply after clearing your regulator?

The primary purpose of exhaling deeply after clearing your regulator is to clear remaining water. When you experience a situation where your regulator may have water in it, clearing the regulator is crucial for ensuring a proper airflow while you're underwater. After this initial clearing, exhaling deeply helps to expel any lingering water that might still be trapped inside. This action not only secures a steady and unobstructed airflow but also enhances your comfort and safety, allowing you to focus on your dive without the distraction or risk of inhaling water.

Other options like filling your lungs with air or equalizing pressure relate to other aspects of diving but do not specifically address the immediate need for thorough clearing of the regulator after water has been introduced. While preparing for a deeper dive is a broad consideration in diving practices, it does not directly pertain to the action taken right after you clear your regulator.