• Breathing under water needs to be measured and relaxed.scuba diver entering the water image by starush from Fotolia.com
  
  Breath control and strength is of the utmost importance for Navy divers. There is a lot of preparation and practice required for these methods. There are several exercises that will help both increase your lung strength and capacity, as well as allow you to get as much oxygen as you can out of each controlled breath.
  
  

Russian Navy Seal Exercise

• For the Russian Navy Seal breathing exercise, submerge into water one end of a 3-foot tube that has a circumference of about the same as a garden hose. Blow through the end above water so that bubbles come up from the other end. As you become stronger with this exercise, you may wish to add a shower head-like nozzle to the submerged end to increase resistance. You can also use either a longer or more narrow tube.
  
  

Tai-Chi Breathing Exercise

• This breathing exercise is recommended by Tom Mount, the president of the International Association of Nitrox and Technical Divers. It helps to regulate breathing so that you are able to consistently take slow, measured breaths.
  
  Lie flat on your back with one hand on your chest, and the other on your abdomen. Slowly breath in for six to eight counts. Be sure that you are breathing into you abdomen so that the hand resting on top is rising as opposed to the hand on your chest. Pause your breathing for a natural one to two seconds, and then slowly exhale for six to eight counts. Repeat this exercise, and increase the inhale/exhale time as you become more relaxed and familiar with breathing into your diaphragm.
  
  

Relaxation and Efficiency

• The purpose of breathing exercises to get as much out your breath, and to make that breath last as long as possible. Therefore, it is important to remember to stay as relaxed as possible. It is also helpful to think about each step of a breath and what it is giving to you. Once you feel comfortable with breathing into your diaphragm, begin to practice breathing as you would once you are under water. Slowly inhale, but not to the full capacity of your lungs. Pause, or hold that breath for a few seconds to allow your lungs to get as much oxygen as possible. Exhale slowly, allowing your lungs to continue to gather oxygen though much of the exhale.