Chapter 6- Rescue and Emergency Procedures Rescue and Emergency Procedures 183 With the integrated regulator mounted on the BC, the methods are somewhat different. The hose is generally too short to allow passage to a distressed diver. In this case, the donor gives the primary regulator from his or her mouth to the out of air diver and puts the integrated regulator into his own mouth to breathe. Because of the duplicate second stage, this ascent can be the most reliable of the dependent methods. However, the procedures must be clear and discussed between buddies before diving. Which second stage will be passed to the out-of-air buddy? Where will the extra second stage be located? The fastest response time has been found to be with passing the second stage from the mouth of the donor and may be of some psychological advantage to the recipient. It is highly recommended that the extra second stage be mounted in the center of the chest for easy accessibility by either donor or recipient. The mounting mechanism must be sufficiently secure to hold the second stage with absolute reliability, yet release easily in minimum response time. Whichever second stage goes to the recipient will, of course, be the one with the longer hose. Another factor to consider is that if one diver is out of air, the companion diver may also be getting low on air. With two divers sharing the same air supply, the demand on that air supply is doubled. The natural stress and anxiety associated with the incident will probably also increase the respiratory demand in both divers. So, the remaining air supply in the donor’s cylinder may be depleted quite quickly. As you can see, there is no standardization of technique for shared air alternate air source breathing. There is continual experimentation with new techniques and equipment. This skill should be practiced regularly with your dive buddy, and certainly whenever you dive with someone new. Shared Air Ascent: Buddy Breathing In the event that an alternate air source is not available, it may be necessary for divers to share a single regulator. Buddy breathing is the most complex of the shared air ascent methods. The out of air diver faces the buddy and signals that he is out of air, and the donor takes a deep breath and passes the second stage to the recipient, who takes two breaths. They then alternate, taking two breaths apiece. Each diver must slowly exhale when the regulator is out of the mouth. Both individuals keep one hand on the second stage (being careful not to cover the purge valve) and firmly hold their buddy with the other. As soon as the breathing cycle is stable (within a few breaths), the ascent should begin. Because both hands are in use, maintaining buoyancy control is more difficult. The ascent must be executed slowly and carefully. Good eye contact will assist in reassuring the person in need of air and will reduce anxiety. To retain the skill of buddy breathing, regular practice is necessary and, certainly, highly recommended. Frequent practice sessions will add confidence and increase the chance of a successful outcome in a real emergency. Determination of which ascent method to use is affected by many factors. The best method for any given situation is dependent upon the circumstances. A controlled emergency swimming ascent is appropriate for shallow water, while an air sharing ascent is preferred for deeper depths. While the safety of these procedures can be significantly enhanced by planning and practice, avoiding out-of-air emergencies altogether is infinitely preferable. Whenever a diver ascends rapidly to the surface, there is an added risk of pulmonary barotrauma and decompression sickness, and further diving must be curtailed. The FIGURE 6-4. OCTOPUS ASCENT
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