SDI Open Water Scuba Diver Practice Exam 2025 – Complete Test Prep

The choice that states the function of the BCD (Buoyancy Control Device) as providing buoyancy control and holding the equipment accurately describes its primary role in scuba diving. The BCD is essential for managing buoyancy; divers can adjust their buoyancy while underwater by adding or releasing air from the BCD, helping them to achieve neutral buoyancy. This means that the diver can comfortably hover in the water column without ascending or descending undesirably.

Additionally, the BCD serves as a mounting point for essential diving equipment such as tanks, weights, and other accessories, keeping them secure and accessible during the dive. This dual function of buoyancy management and equipment carrying is crucial for safe and effective diving.

The focus on thermal insulation, storage for personal items, or navigation does not align with the BCD's primary intended functions. While divers may wear exposure protection suits for thermal insulation, and personal items can be carried in other types of gear or bags, these do not pertain to the specific roles of the BCD.