When wearing an exposure suit, where should you add air to control buoyancy?

When wearing an exposure suit, air should be added to the buoyancy control device (BCD), which is commonly referred to as a BC vest. The purpose of a BCD is to help divers manage their buoyancy by adjusting their air volume while underwater.

As divers descend, they can deflate the BCD to decrease buoyancy and allow for descent, while adding air to the BCD during ascent helps increase buoyancy, allowing the diver to control their position in the water column, stabilize at various depths, and facilitate safe ascents and descents. This control is crucial for maintaining neutral buoyancy, which keeps the diver from sinking too deep or ascending too quickly.

Adding air to other options such as the tank or breathing regulator is not appropriate for buoyancy control. The tank is a source of compressed air for breathing but doesn't impact buoyancy directly, while the breathing regulator is designed to deliver air to the diver from the tank but also does not play a role in buoyancy control. Adding air to the diving mask is not relevant to buoyancy as the mask's function is solely for vision and comfort underwater.