To prevent air embolism, a diver should breathe _______ at all times during ascent.

To prevent air embolism during ascent, it is crucial for a diver to breathe normally. When a diver ascends, the pressure around them decreases, and air expands in their lungs. If a diver were to hold their breath or breathe incorrectly (such as quickly or shallowly), this could lead to the expansion of air in the lungs, creating a risk of over-expansion and rupturing lung tissues. By breathing normally, the diver allows for the safe exchange of air in and out of the lungs, which helps maintain appropriate pressure balance and prevents the formation of gas bubbles in the bloodstream that could lead to air embolism.

While breathing deeply or quickly may seem beneficial for other activities, in diving, it can do more harm than good. Deep breathing can increase the volume of air in the lungs too quickly, while rapid or shallow breathing may not adequately remove air from the lungs, increasing the risk of problems during ascent. Thus, maintaining a normal, steady breathing pattern is the safest approach to prevent air embolism.