When diving doubles you will need to use your wing/BCD to compensation. Typically you can't control your buoyancy only with a drysuit with steel doubles and stage bottles so you will need to use your wing to offset buoyancy.
The structure of the throat is designed to prevent food from entering the lungs. Photo Credit matthewennisphotography/iStock/Getty Images. When food enters the lungs instead of the esophagus, it affects breathing and can cause choking and other problems.
1 The other is the trachea, which is the opening air must pass through to get to the lungs. 2  When swallowing occurs, the trachea is covered by a flap called the epiglottis, which prevents food from entering the lungs. 3  The trachea splits into the left and right main stem bronchae. 4  These lead to the left and right lungs.