Learning to dive is required to be physically healthy, without the following contraindications:
1. ever received middle ear surgery, or cornea surgery; 2. a history of lung injury, especially spontaneous pneumothorax; 3. severe obstructive lung disease, such as chronic emphysema or severe asthma; 4. alveoli with congenital diverticulum or pulmonary blister disease; 5. a history of epilepsy or cramp; 6. frequent fainting with unknown cause; 7. coronary artery disease of the heart, such as angina pectoris or a history of myocardial infarction; 8. erythrocytic lesions, such as sickle cell anemia; 9. insulin-dependent diabetes mellitus; 10. chronic alcoholism or drug addiction; 11. psychiatric disorders
People with the above problems can not withstand too much exercise or can not be psychologically Moderate debugging, easy to danger, so it is not suitable for diving, but you can learn to snorkeling, snorkeling in good visibility can also enjoy the gift of the sea to you!
Can I dive if I have a cold?
Diving when you have a cold is not recommended, and unless you answer 'YES' to all of the following questions, you're better off staying out of the water when you have a cold. With one nostril plugged, can you easily breathe through the other?
If you have a cold, do you not have to wring your nose for at least two hours?
Can you easily do ear pressure equalization on shore?
Is it at least a day since you had a fever or cold sweat?
If you have a cold, have you not had a cough for at least two hours?
If you are taking medication, is your next dose at least two hours after the dive?
If you are a diver who needs vision correction, can this problem be solved?
Yes, you have the option of purchasing face lenses with myopic lenses. However, if you wear contact lenses, soft contact lenses are generally fine but not recommended.
What is ear pressure equalization?
Ear pressure equalization is the technique of making the pressure in the ear the same as the surrounding ambient pressure in a certain way. A common method is to pinch the nose and puff out the air, pinch the nose from the nose pocket of the mask, make the nostrils blocked, and then gently use the nose to breathe out, then you will feel the eardrums bulge outward and there is a "giggle" sound.
In addition to the method of pinching the nose and puffing, you can also achieve ear pressure balance by swallowing, yawning, or swinging your jaw from side to side
What are the six golden rules for ear pressure balance?
1. Start your ear pressure equalization before you even dive!
2. Do it every few meters after the dive to avoid discomfort!
3. Don't wait until you feel uncomfortable (or in pain) to remember to start doing it!
4. If you can't do it with ear pressure, rise a little and try again! Try letting the face mirror get water in before draining it! If you really can't equalize the ear pressure after all that effort, give up on the dive!
5. If you are having trouble balancing your ear pressure, try using a dive rope, feet down, and dive slowly.
6. Never pinch your nose and puff too long or too hard! You risk injuring the cochlea and ear drum!
What should I do if I have an earache or tinnitus after a dive?
Possibly water in the ear or choking on the nose, drainage methods
1. Tilt your head to the side of the ear into the water, pull on the earlobe, and use the same side of the leg for a one-legged hike
2. Palm of your hand to the ear canal, use your hand to block the ear tightly and press it tightly. A cotton swab is sent into the ear canal to suck out the water
What are the safety rules for divers?
1. Be in the best physical and mental condition
2. Be a strong swimmer
3. Receive proper training instruction
4. Establish a dive plan and dive according to the plan
5. Familiarize yourself with the area, and dive in unfamiliar areas with someone familiar with the area
6. Carry first aid supplies
7. Carry first aid supplies
7. Measure your ability (yourself and your equipment)
8. Check your gear and use it in good condition
9. Use all necessary equipment
10. Fish guns should be considered as a dangerous device and should be used with caution
11. Never dive alone and never leave your buddy
12. Balance ear pressure before feeling discomfort in the ear
13. Get out of the water and get to shore quickly if you are injured, fatigued, or uncomfortable
14. Pay attention to depth and time, and ascend carefully and correctly
15. Snorkeling experience is essential for scuba diving
16. Observe the dive depth limits, and even proficient air divers should try to avoid depths greater than 30 meters (100 feet). 30 meters (100 feet), never more than 39 meters
17. Knowledge and application of underwater communication methods
18. Scuba diving must maintain a deep inhalation and slow exhalation breathing
19. Repeat dives should pay attention to the order of the dive, avoid decompression dives, and do a safe decompression
20. 21. High pressure cylinders should be well maintained and handled correctly
22. Regular maintenance of equipment is required, cylinders should be visually inspected externally at least 1 time per year, and hydrostatic pressure tested at least 1 time every 3 years
What is decompression sickness?
Decompression sickness, known as Decompression Sickness (DCS) in English, occurs when you dive to a depth of more than 10 meters or work in a chamber pressurized to 2 atmospheres for more than 50 minutes, and then after the dive or work in a high-pressure chamber, the inert gases (e.g., nitrogen (N2) or helium (He)) that are trapped in your joints or tissues are unable to circulate with your blood due to improper decompression. The inert gases (such as nitrogen N2 or helium He) that remain in the joints or body tissues due to improper decompression are unable to be sent out of the body with the blood circulation and form bubbles, resulting in physical discomfort or acute disorders, known as decompression sickness or Caisson Disease.)
What are the types of decompression sickness?
Decompression sickness can be divided into three types according to the symptoms: decompression sickness type I, decompression sickness type II, and chronic decompression sickness.
Decompression sickness type 1 is mainly caused by inert gases that form bubbles and then clog up the subcutaneous tissues, joints, or muscles, causing severe pain in the joints and affecting the ability to act, and its main symptoms include itching, tingling of the skin, rashes, and pain in the joints and muscles.
Decompression sickness type 2 is mainly due to gas bubbles in the body's respiratory system, circulatory system or the nervous system caused by the body's functions of the serious obstacles to shock and death, the main symptoms are: dizziness, blurred vision, nausea, vomiting, ringing in the ears, dizziness, speech impediments, visual blurring, limb numbness, difficulty in coordinating, chest tightness and chest pain, blindness, shock, and death.
Chronic decompression sickness refers to the long-term exposure to abnormal air pressure staff, due to improper decompression, resulting in chronic damage to the central nervous system or body tissues; its main symptoms are: inattention, vision loss, memory loss, slow action, behavioral abnormalities. There is also Dysbaric Osteonecrosis (Dysbaricosteo-necrosis), a non-traumatic and non-infectious ischemic necrosis that usually occurs in the long bones of the limbs of professional divers or hyperbaric operators, especially the femur and humerus.
How can decompression sickness be managed as well as prevented?
1. It is best to have the patient lie down during transport to the hospital, unbound (e.g. dive suit, etc.), with feet padded about 20-30 centimeters high to avoid danger due to air bubbles clogging the blood vessels or the nervous system in the brain.
2. Don't let the sick person drive by himself, in order to avoid danger due to sudden muscle and joint pain.
3. Keep the patient under normal pressure, do not take an airplane to transport at high altitude, so as to avoid deterioration of the patient's condition due to the drastic change of air pressure, which the patient can not withstand.
4. Use the oxygen equipment in the ambulance to relieve pain and pressure.
Decompression sickness is not a disease that will definitely occur, nor is it unique to dive professionals, how to do a good job of prevention and planning before each job is very important, in addition to the preparatory work beforehand, the cognitive and decompression procedures must be confirmed again and again to ensure safety.
(1) Strengthen the correct concept and formal training of divers or abnormal barometric engineering
(2) Implementation of correct and accurate decompression procedures
(3) Diving equipment and construction equipment maintenance and attention
(4) Regular health checks and attention to personal illness
What are the circumstances of the cramps? What should I do when I get cramps?
Cramps can occur if you are nervous, if the water is too cold, or if you stay in the water too long. You should prepare yourself well before going into the water and not stay in the water for too long. Once cramps occur, do not panic. Than toe cramps, then immediately bend the leg, and force the toes to pull apart and straighten; if the calf cramps, use your hand to pull the top of the frog shoes in the direction of their own body, and make the calf stretched forward stomping, so that the contraction of the muscles to stretch and relax, followed by the hand gently rubbing the calf's muscles; finger cramps, the hand clenched into a fist, and then force to open, and so on and so forth.
How do I handle nausea and vomiting?
Get ashore quickly, then use your fingers to press the middle and inner acupuncture points, or if you have Rendan, you can also contain a capsule.
What should I do if I have itchy skin or rash after diving?
Mainly due to skin allergy. If you go ashore immediately and take a tablet of Xismin or Paracetamol, you will feel better soon.
What should I do if I have a headache while diving?
The cause may be chronic rhinitis, choking or cold body, temporary cerebral vasospasm and cause insufficient blood supply. This time should be quickly ashore, with the thumb on the top of the head of the Hundred Club, the sun and the Liechao points to rub, and then use a hot towel on the head, and then drink a cup of hot water, you can get better.
What about diving?
Just after eating or diving on an empty stomach will produce abdominal pain and bloating. Then you should go ashore and lie on your back, use the tip of your thumb to press the middle and upper epigastric region or the foot, while taking 3 to 5 milliliters of 10 drops of water orally, and use a hot towel to compress the abdomen.
How to deal with itchy and painful eyes?
It may be caused by unclean water. Immediately after disembarking, you should rinse your eyes with clean, saline water, then use chloramphenicol or erythromycin eye drops, and it's a good idea to do a hot compress before you go to bed.
Air embolism (AGE, arterialgasembolism)
Recreational diving in addition to decompression sickness, air embolism is also one of the main protagonists of the major injuries caused by divers to dive medical alert network DAN, diversalertnetwork) information shows that 58% of the air embolism patients in the The first time I saw this, I was in the middle of a dive, and I was in the middle of a dive, and I was in the middle of a dive, and I was in the middle of a dive, and I was in the middle of a dive.
The main cause of air embolism is the inappropriate holding of breath during the ascent of the dive, resulting in the body's air can not be discharged, the lung tissue is overstretched and damaged, rupture of the alveolar membrane, the air enters the circulatory system through the rupture, blockage of the coronary arteries or capillaries in the brain, resulting in shock, "spasms," arrhythmia, loss of consciousness, and in severe cases, death. Loss of consciousness, severe cases produce death.
Causes of diving headaches
Hypoxia
Hypoxia is a condition in which the body's organs and tissues are unable to obtain enough oxygen from inhaled gases to maintain their normal functions. The tolerance and symptoms of hypoxia vary greatly from person to person.
The causes of hypoxia in diving are:
1. During the ascent, the partial pressure of oxygen decreases, which is insufficient to supply the diver with the required amount of oxygen, resulting in hypoxia.
2. Intermittent breath closure by the diver to save air consumption. Although deep inhalation and slow exhalation breathing method, but the inhalation and exhalation of the intermittent time is too long (no coherent inhalation and exhalation).
3. In cold waters or during intense workouts that increase the amount of oxygen consumed, there is no relative increase in the amount of oxygen supplied by the cylinder, resulting in insufficient oxygen.
4. Dislodging of the secondary head, malfunctioning of the air supply system, malfunctioning or broken air supply lines.
5. Failure of the first and second stage head air valves, resulting in abnormal gas output. Insufficient, interrupted or depleted gas flow in the air supply system. (Depending on the brand, the pressure in the first stage head is about 8~12 bar, and the pressure around the second stage head is 1 bar)
6. Oxygen concentration in the supply gas is too low (below 21%). Incorrect mixture ratio of air compressor.
1. Rapid symptoms of hypoxia may include unconsciousness in the water without warning, loss of consciousness, euphoria, excessive self-confidence, apathy, etc.; rising to the surface of the water may result in a loss of consciousness. Indifference, etc.; also fatigue, headache, dizziness, amblyopia, etc. after rising to the surface.
2. Slow hypoxia will have symptoms such as poor coordination of movements in the water, poor operation, poor judgment, and weakened memory.
Carbon dioxide poisoning
The purity of carbon dioxide in diving air should not be more than l000ppm. The causes of carbon dioxide poisoning are:
1. Divers are afraid of not breathing enough air, so they will not consciously lengthen the time interval between breaths, intermittent breathing, or closed breathing, thus resulting in the accumulation of carbon dioxide.
2. The air compressor in the filling store does not have carbon dioxide absorbent, the carbon dioxide absorbent is damp or old, or the carbon dioxide filtration (filter center) system is not working.
3. Almost all brands of underwater rebreather (regulator) more or less have carbon dioxide exclusion problems, due to design flaws, part of the exhaled gas carbon dioxide retention in the dead space of the rebreather, coupled with the mask or full, half-masked dive helmet oxygen ventilation is poor, resulting in a rise in the partial pressure of carbon dioxide.
4. The dead space in the rebreather is too much, which will easily cause carbon dioxide to accumulate over the standard value.
5. Excessive work or intense exercise in the water by divers can cause carbon dioxide retention and increase the risk of poisoning.
6. The air source used for filling is polluted air (especially air compressors located in urban areas), air compressors are poorly maintained, using the wrong oil or lubricant to produce exhaust gas, and many pollutants including carbon dioxide will enter into oxygen cylinders if they are filled in such an environment. Breathing contaminated air can cause headaches, nausea, and dizziness, but some are odorless and tasteless, which can cause sudden unconsciousness without warning.
The course of symptoms of carbon dioxide poisoning are:
Shortness of breath, euphoria, a feeling of tiredness, headache, dizziness, vomiting, confusion, unconsciousness, coma, and death.
How to save yourself from sudden sinking while swimming?
This danger is common among beginner swimmers or those who are not good at swimming. In the middle of swimming, you may feel that your body suddenly loses its strength and sinks. This situation is mainly due to the lack of estimation of their own physical strength, uneven distribution of physical strength, physical exertion is too large, they do not realize, in this case, must remain calm, can be in the body when the sinking closed breathing, so that the lungs of the body full of gas, a few moments, the body will naturally float, and then, rowing a small breaststroke hand (hand downward pressure paddling), stirring a small breaststroke legs (mainly calves, ankles from the inside to the outside of the paddling circle), and gradually transition to breaststroke. Gradually transition to breaststroke. If you have a water line or other aids around you, you can take a break and swim again.
How can I save myself from being entangled in water plants in natural waters?
When swimming in natural waters, it is important to observe the underwater environment first. If you are unfortunate enough to get entangled in water plants or fishing nets, you must stay calm and never struggle. The only way to get free in this situation is to remain calm. The earlier the entanglement is detected the easier it is to free yourself. After being entangled, you should first relax your body, observe the entanglement and look for a way to free yourself, and if you can't free yourself, you can call out for help. (Water plants and the tip of the entangled rope will spread outward and upward as your body relaxes, so if you look carefully for the root cause, you will be free.)
When you or your dive buddy is in danger, how do you save each other?
The technique of mutual aid for divers mainly refers to the first aid measures to be taken when two divers are diving in pairs, in the event that one of the rebreathers malfunctions and causes an interruption in the air supply.
The steps are as follows: two people face each other at a distance of about 10cm; the person who supplies the air takes a full breath and hands the mouthpiece to the person who needs it; the person who needs the air first exhales to get rid of the water in the mouthpiece, then inhales two breaths and hands the mouthpiece to the person who supplies it, and so on and so forth, while continuously rising up to get out of the water
How can I avoid the bite of organisms in the water?
1. Practice perfect neutral buoyancy and avoid touching any creatures
2. Be aware of your surroundings at all times during the dive
3. Look up and pay attention to your surroundings when ascending or descending, and pay special attention to areas where jellyfish are likely to be found
4. Pay special attention when stepping into sand or mud as there is a high probability that a dangerous creatures
5. Avoid taking freshly hunted fish with you, and be especially careful if diving in areas where sharks are likely to be present
6. Consider the location of dangerous creatures and avoid them as much as possible
7. Regardless of the temperature of the water, wearing cold-weather clothing protects our bodies from other creatures
8. Avoid feeding or catching fish to avoid unnecessary accidents
9. To avoid unnecessary accidents
9. Avoid balancing on the reef with your hands when taking photographs
10. Don't pick up shells
11. Make sure that the items in your first aid kit are appropriate for diving injuries and that your medications are not out of date
12. Learn the basics of rescue, including emergency treatment of biological injuries, etc., which all participants in water sports should learn. All participants in aquatic activities should learn CPR and first aid
How can you avoid the panic that threatens you?
1. For divers who haven't been in the water for a while, getting in the pool first and practicing basic maneuvers will definitely help your confidence
2. Make a good plan before you dive, and follow your plan when you dive
3. Discuss diving techniques with your instructor or divemaster
4. Discuss any problems you may have with your instructor and learn how to deal with them beforehand
5. Never dive beyond your training or ability