BCD — Buoyancy Compensator Device

A BCD is a jacket or wing that holds air to control your position in the water. You use it to stay at a specific depth without working too hard. Most divers use it to manage buoyancy during descents and ascents. In Koh Tao, I often saw beginners struggle with overinflating their BCD because they forgot to check the pressure gauge. This mistake causes a rapid, uncontrolled ascent toward the surface.

You should always vent air before you reach the surface. If your BCD is too big, it will feel bulky and restrict your movement. A well-fitted wing allows for better trim while you swim through narrow reef cracks. Check your inflator hose for leaks every single time you gear up. Small leaks can ruin a dive if you lose buoyancy at 18 m.