One of the features of safety technology diving is the complexity of equipment. Recreational divers have the opportunity to reach the water quickly. Technical divers, however, have no such treatment, so they must be more self reliant. Murphy's law, for technical diving, means that two of the same equipment should be seen as a gear. When a diver uses only one particular piece of equipment, he has to plan how to complete the dive without losing the equipment. Ignorance of the law can lead to disaster.
That dive?
Trevor, a 30 year old junior, is an experienced technical diver and coach. At the time, he was working with two experienced students in a series of deep (deep) air diving training, and several diving, in order to check equipment configuration. After several days of lessons, Trevor completed three dives at about 200 feet (about 61 meters) and about 150 feet (about 46 meters) in depth at a technical diving training point in North Florida, two times.
During these freshwater activities, they carried a mixture of water at the bottom of the water and 80% nitrogen to reduce pressure from 30 feet (about 9 meters) to the surface of the water. Each diver carries the right amount of redundancy: double cylinders with separate manifolds, dual air pressure valves, independent pressure relief cylinders, and pre stored pressure gas for emergency use. Divers use dual computer watches, or computer tables with depth meters, timers, and pressure gauges for emergency use. Trevor not only has two computer watches, but also comes with a watch and depth gauge for standby.
All the diving activities went very smoothly. In addition to training scuba diving, Trevor also completed an independent dive in second days to check the equipment and completed a single recovery kit in third days. All divers to maintain adequate moisture and fully rest over the weekend, Trevor also serve keep rising rate constraints, scheduled decompression and additional safety stop stop. Following the dive, the divers completed 30 minutes of surface decompression and immediately began the arduous task of bringing their technical equipment home.
Symptoms and treatment
About 2.5 hours after the dive, the divers stopped and prepared a routine dive. While enjoying the meal, the coach suddenly showed the symptoms of DCS: sudden attacks of extreme fatigue, numbness in the hands, and partial weakness of Zuo Banqu. Symptoms were discovered immediately. The instructor immediately breathes pure oxygen and begins intravenous injection and is immediately transferred to a nearby high pressure cabin. Emergency medical staff quickly diagnosed the symptoms, immediately under the "Navy high pressure treatment schedule 6" for coaches of a series of symptoms for treatment.
(Note: Navy hyperbaric therapy schedule". An emergency hyperbaric oxygen therapy schedule for diving disorders based on "Navy diving decompression tables" used in Canada and the United States
accident analysis
Although the outcome was satisfactory, all divers questioned about the incident and what went wrong. The answer is redundant standby gear.
Each diver's computer table is accompanied by an independent archive of its own. Trevor uses a state-of-the-art, "no hose," air pressure diving computer watch". This computer table before several problems, but also has repeatedly returned to factory maintenance. Trevor has just retrieved this adjusted, verified, safe computer from the manufacturer. Unfortunately, this computer table is not safe for him because the computer tables provide incorrect depth information and decompression records. Although Trevor carries two computer watches, another computer is considered an alternative to system errors.
(Note: "no hose, air pressure diving computer", refer to the ScubaPro Galileo series diving computer)
Trevor had never checked his backup computer before the final stop of this series of dives. When the last decompression stopped, the main computer stopped providing the correct information, and he used the timer for the last safe stop. To be on the safe side, he used 80% nitrogen at 15 feet (about 5 meters), adding an additional 10 minutes to a safe stop. At this stop, Trevor checked the backup computer, but was surprised to find the computer locked in the "air pressure" mode". In a subsequent comparison of the Trevor computer with other divers' computer tables, it was confirmed that his main computer continued to provide false decompression files for the last two or three days.
(Note: barometric mode. Some of the special features of a diving computer are provided by combining the cylinders with only air pressure status and content
Lessons of life
1, for technical diving, complex equipment must be durable and should be periodically checked during diving to ensure its normal operation.
2, electronic devices, such as computer watches, may inadvertently cause errors. The diver must be alert and cross checked with the standby computer to select and follow the more conservative computer to provide information.
3, divers must not use recently repaired or new equipment to perform challenging dives unless normal function is verified in shallow and protected dives.
4. Never delay treatment when you suspect DCS. In this accident, the rapid response to the symptoms of DCS brought about satisfactory results.
5, all divers should perform oxygen management, CPR (cardiopulmonary resuscitation) and basic first aid training. Fortunately, the divers in the accident took proper training and equipment,