What does "equalization" refer to in diving?

Equalization in diving specifically refers to the process of balancing the pressure in the middle ear with the external water pressure as a diver descends. As a diver goes deeper, the water pressure increases, which can create a pressure difference that may lead to discomfort or injury if not properly managed. To equalize, divers typically perform techniques such as the Valsalva maneuver, which involves pinching the nose and gently blowing to force air into the Eustachian tubes, thereby equalizing the pressure. This process is crucial for safe diving, particularly in preventing barotrauma, which can occur if the pressure difference is not addressed.

The other choices do not accurately define equalization. Adjusting equipment for comfort relates to fit and comfort rather than pressure management. The act of descending into the water is a general diving action and does not specifically pertain to pressure equalization. Similarly, managing buoyancy underwater involves controlling one's position in water but does not involve pressure balance, which is the essence of equalization. Understanding this concept is vital for divers to ensure their safety and comfort underwater.