The first day of open water diving certification begins in the pool, where the controlled setting helps to focus on technique without the distraction of waves or visibility issues. The training depth is around three metres, which is enough to get a real sense of being underwater while still within the safe boundaries of a swimming pool. Much of the day is spent learning to equalize, clearing the mask, and practicing buoyancy. These are small but essential steps, and repetition helps build comfort with the equipment and the idea of breathing underwater for long stretches. The controlled pace of the session allows the body and mind to gradually accept the new environment.
Equalizing is one of the first challenges to get right. As the body descends, pressure builds in the ears, and it has to be released by pinching the nose and gently blowing or using swallowing techniques. At three metres it feels manageable, but the reminder is constant that as the depth increases, this becomes a critical part of safe diving. Practicing equalization several times during short descents helps build a natural rhythm. It is less about strength and more about awareness, noticing the point at which pressure begins and addressing it early. The instructors emphasize frequency over force, since waiting too long makes it harder to equalize comfortably.
Mask clearing comes next, and while it feels awkward at first, the process is designed to handle one of the most common situations under water. Filling the mask with water and then pushing it out by pressing the top frame while exhaling through the nose is a basic but vital skill. It teaches trust in the equipment and confidence in managing discomfort. At first, water against the eyes and nose feels unnatural, but repetition shows how quickly the body adjusts. This exercise also ties back into staying calm and not rushing through actions, as panic only complicates simple procedures. The pool setting makes it easier to practice without pressure.
Buoyancy control rounds out the essentials of day one. Learning to hover, adjust breathing, and manage air in the BCD (buoyancy control device) shows how fine the balance is between sinking and floating. At three metres, small shifts in breath or movement make noticeable changes, which makes it the perfect environment to experiment. The importance of slow, deliberate breathing becomes clear, as it affects not only air consumption but also stability under water. By the end of the day, the connection between breathing and control feels stronger, even though mastery is still far away. The repetition is tiring but rewarding.
Looking back at the first day, it becomes clear how each of these skills is a building block. Equalizing, mask clearing, and buoyancy may seem basic in a pool, but they prepare for the open water dives where conditions are less predictable. The process is structured in a way that slowly introduces both the technical and psychological aspects of diving. Getting comfortable at three metres is a small but necessary step toward going deeper, and the day ends with a sense of both fatigue and anticipation for what follows in the sea.