Immersion reflex: Does not conserve oxygen to the body Oxygen consumption will increase to produce more heat to the body You burn more of your bodys fuel and you increase your metabolism Blood slows to the extremities and stays in the head and thorax region of the body
Secondary Drowning: Drowning that occurs post immersion Ingestion of water into the pulmonary systems Known to have occurred hours after swimming Prognosis is good if occurred in fresh water 90% of victims are from fresh water
Chances of Survival: The golden hour is a myth. Real Chance: 3 minutes. Possible Chance: 10 minutes. It is all dependent on the temperature of the water (Less than 50 F). There are rare cases of survival submersion for extreme lengths of time. Children have a better chance than adults
Mechanics of Drowning Dry Wet 10% to 15 % drownings Laryngospasm Possibility of Resuscitation No water in lungs, death may have occurred prior to submersion 85% to 90% of drownings Agonal gasp Water aspirated into lungs Water in lungs death occurred after submersion
Two Types: 1. Drowning: Death by from suffocation (asphyxia) caused by liquid entering the lungs and preventing the absorption of oxygen leading to cerebral hypoxia and myocardial infarction. 2. Near drowning: the survival of a drowning event involving unconsciousness or water inhalation and can lead to serious secondary complications, including death.
Scenario: A boater, who does not know how to swim, takes off his PDF for a quick dip off the back of the boat, while holding on to the boats swim step. While trying to get back into the boat, he loses his grip to the swim step and it is now too far away to grab it. He tries to keep his head above water and at the same time holds his breath. Panic has set in. His body movements become more frantic and his body uses up its oxygen in the blood stream. This will reduce the time until unconsciousness. Meanwhile, carbon dioxide levels are building in the victim, leading him to a stronger desire to breathe.
The victim can no longer voluntarily hold his breath. The conscious victim will now have water entering his airways. He will try and cough up the water or swallow it, but he will involuntarily being inhaling more water. As the bodys defense, the victim will go into laryngospasm and the water will enter the victims stomach. Little water will actually enter the lungs. After the laryngospasm, the victim will become unconscious and the laryngospasm will relax. Again, the body will go in defense mode and try and get oxygen into the system. This lack of oxygen in the brain, or Hypoxia, will cause the brain to trigger breathing to survive.
The brain now triggers agonal breathing. This with the relaxation of the laryngospasm, will now cause water to enter the victims lungs. The lungs are being collapsed at the same time deterioration of the brain cells are beginning. Additionally, a lack of oxygen and chemical changes in the lungs, cause the heart to stop. Cardiac arrest ensues and blood transportation stops throughout the entire body. The brain, the last and most critical organ begins to die. After six minutes the brain is dead. Two hours later, Rigor mortis will set in and it will stay there for up to two days.
Crime Scene: Identify Evidence Types of evidence Witness interviews Does it all make sense???
Physiological changes in the human body Rigor Mortis Livor Mortis (Absence/Contact) Cadaveric Spasm Decomposition Putrification Anthropophagy
Interviews Photography/Videography Topside documetation Mapmaking Written Report Accuracy
Preserving the interior Evidence Recovery vs. Salvage Hazards Vehicle inspection Accident analysis
Surrounding Area Handling/Bagging Rigor Decomposition Contamination
Why do dry suits require a special zipper? What are the most common types of dry suit seals? What is the Carotid Sinus reflex and how do you prevent it? What two valves do all dry suits have, and what are each used for? Entry?
What are six considerations when choosing dry suit undergarments? Cost Thickness/insulating ability Insulation characteristics when wet Care Bulk Fit Common Types of undergarments: Pile Bunting Open cell foam Thinsulate Depending on water temperature, it may be wise to additional layers of insulation.***
How do undergarments keep dry suit divers warm? Trap gas, which has low heat capacity and therefore slows the rate at which water outside the suit carries away body heat. Material may have qualities that enhance the insulation of the surrounding gas. When out of the water, not wearing the dry suit, trapped air in the undergarment insulates because it does not readily pass heat to cold air outside of the suit.
Weights Why do you sometimes need more weight when diving with a dry suit than with a wet suit? Diving with a larger amount of trapped air in the suit Amount of weight needed to dive depends on the material of the suit thats why pool dive is important May need significantly more or a little more. Can your current weight system handle the additional weight? You can redistribute weight so that you dont have all your weight in a single system. Accessory weights (tanks and ankles) Pros and cons of weighting system (belt vs. harness) For weighting, determine the proper weight the same as you would with any new equipmenttry it in the pool
BCD Why do you always use a BCD when diving with a dry suit? Emergency buoyancy if you have a leak in your suit More comfortable way to float on the surface Make sure your BCD fits over the dry suit Adding air to the dry suit will make it balloon around the neck making it uncomfortable. Only add a little to relieve suit squeeze.
As you descend, lower your left shoulder so gas does into escape from the exhaust valve. When adding gas to your suit do so slowly After starting your descent, you can shift to a spread eagle position, or cave diving position, to help distribute the gas evenly. Regardless of the dry suit type, you control your buoyancy with your BCD and add just enough air to prevent squeeze. During ascents vent gas automatically or manually When using an automatic valve open it all the way to release gas easily As you ascend, raise your left shoulder or wrist (the exhaust valve) to vent the gas and/or press the valve. Do this in conjunction with the BCD.
General Care: Rinse the suit in clean fresh water after diving. Rinse the interior if the suit leaked or you perspired excessively. Flush the inflator and exhaust valves thoroughly with fresh water. Hand to dry over thick bar that avoids a sharp bend. Do not hang in direct sun light. Zipper Care: If necessary, gently clean inside and out with a soft tooth brush dipped in soapy water to remove dirt or debris. Use only paraffin zipper wax to lubricatenever use silicone spray. Lubricate before storage.
Storage: Dust Latex and neoprene seals (and latex boots) with pure talcum powder or as directed by the manufacturer. Tuck latex seals into the sleeves and suit body. Loosely roll or fold suit with valves on the outside and the inlet stem capped to avoid punctures. Store away from heat, oil, and chemicals. Store in dark, cool and dry area. Transport: Pack folded as for storage. Pack suit in its own bagseparate from other equipment. Pack it in a way as to not stress the zipper
Different materials require different procedures. Make sure to follow manufacturer instructions. Major repairs, such as large holes/tears, valves, and boots should be done by the manufacturer or a qualified vendor to ensure quality. Repairs of seals is a somewhere between moderate and major repair. When in doubt, check with the manufacturer.
Inflator valve stuck open or leaking gas: Cause: poor maintenance (corrosion build up) or valve freezing in very cold water Prevention: Proper maintenance, annual suit servicing; add gas in short bursts. Correction: Disconnect the inflator hose and dump excess gas immediately. If you cannot vent the gas fast enough, flare your body while dumping excess gas through a valve or seal. Exhaust valve stuck open: Cause: Poor maintenance; no predive check of valve Prevention: Proper maintenance, annual servicing. No predive check of valve Correction: Vent gas through neck and wrist seals (attached hood). If available use ascent line to slow rate. Flare body and dump air any way possible. End dive.
Lost weights (unable to recover): Cause: Improper release attachment, mishandling, buckle tripped on underwater object, failure to inspect weight system predive Prevention: Be familiar with your system and inspect weight system before every dive. Correction: Flare and dump. Overweighed: Cause: Overweighting is offset by more gas in suit. During ascent, excess gas expands faster than can be vented through exhaust valve. Prevention: Dive properly weighted. Correction: Stop ascent and allow exhaust valve to catch up. If cannot stop, dump and flare.
Handling excess gas in the legs of a dry suit: Cause: Excess buoyancy and allowing legs to get above shoulders Prevention: Do not ascent with feet above shoulder level. Wear gators to prevent excess air in legs (Cave diving position). Correction: if possible grab something to slow ascent, roll forward or backward, use BCD, to get legs underneath you.
Handling a flooded suit: Causes: Zipper not being closed, damaged zipper, material caught in zipper, seal leakage or valve leakage Prevention: Proper getting into suit, maintenance, and care. Check zipper and be sure it is closed properly before diving. Correction: Terminate dive immediately. Use BCD for buoyancy if necessary.
Helmet Yokes Dry Glove Systems Inflation Systems