Navy officer, 35, dies in off-duty diving mishap

If I read this a year ago I might have opted not to go diving for the first time myself in Hawaii last July when I was orders working for PACOM.

Navy office is die reason and everything is mention in the blog and you can easily read https://bestwritingsclues.com/reviews/bestessay-review/ and all the reason which is mention. He is such a good guy because he die to save our nation and is seriously responsible to save our live.

I used rebreathers during my time in the Navy. Most recreational divers don’t realize that have an inherent risk greater than that found in open circuit scuba. Diving with rebreathers demand a considerable amount of instruction to instill respect for the potentially fatal problems associated with rebreather diving, and active rebreather divers must take care not to become complacent. The Navy does a good job with that task; the civilian world (as with parachute training ) does way less detailed training and/or safety checks.

Because rebreathers recirculate a portion of each exhaled breath, carbon dioxide (CO2) generated by the body's use of oxygen must be eliminated before the gas can safely be returned to the diver. Failure to remove CO2 can cause hypercapnia - whose signs and symptoms include dyspnea, confusion, drowsiness, rigidity, spasms, loss of consciousness, and headache. CO2 is removed by directing exhaled gas through a CO2 "scrubber." The carbon dioxide in a diver's exhalation combines with water vapor in the loop, forming carbonic acid which is easily neutralized with a base material. Halcyon's rebreather scrubber is packed with a base material such as Sofnolime. As the carbonic acid passes through the scrubber, the CO2 molecules bind with the base material granules, neutralizing the CO2 from the exhaled gas. The byproducts of this chemical reaction are the formation of chalk, water vapor, and heat.
Here’s a few areas that can be deadly:
- BYPASS OF CO2 SCRUBBER: a rebreather is designed to allow gas to flow through the loop in only one direction through the scrubber, one-way valves are used on both sides of the mouthpiece. Should a one-way valve fail, the CO2-laden gas could simply flow back and forth in the hose without going through the scrubber.
- FAILURE OF CO2 SCRUBBER: hypercapnia may also result from dives that exceed the scrubber material's duration. Rebreather divers must know how long their scrubber will last in the environment where they are diving. Certain environmental conditions, such as cold water, greatly reduce the scrubber material life. Water infiltration, either by a leak or condensation, into the scrubber can also reduce the efficiency of the scrubber medium. Divers who frequently reuse or are careless about replacing the scrubber medium are most likely to experience these problems.
- CHANNELING DUE TO A POORLY PACKED SCRUBBER: for CO2 to be eliminated, it must come in contact with the scrubber medium. As the exhaled breathing mixture will flow through the scrubber along a path of least resistance, any pockets or voids in the scrubber media will allow some gas to pass through the scrubber with only a partial reaction to the medium. Care must be taken to ensure the scrubber media is thoroughly and correctly packed to avoid the gas forming channels, and thereby compromising the scrubber's effectiveness.
- FLOODING: water vapor is necessary to form the carbonic acid required to catalyze the CO2, large volumes of water in the scrubber will insulate the media from any gas flowing through the scrubber. It is imperative that all system integrity checks be done prior to every dive.
- HYPOXIA: if you’ve dove with Nitrox, you are familiar with the problem of too much oxygen (hyperoxia). However most recreational divers are not familiar with the problems of too little oxygen (hypoxia) which occurs when tissue cells are unable to receive sufficient oxygen through the arterial blood to maintain function.