The thickness of diving suit is generally required to be at least 3mm, which can not only provide divers with certain buoyancy, but also prevent the body temperature from dropping too fast. The thickness of jellyfish skin is generally 0.5 ~ 2 mm.

2. Function

Diving suit: keep warm; Give divers a certain buoyancy; Protect divers from rocks or harmful animals and plants.

Jellyfish skin: heat preservation; Waterproof mother and stabbing; Provide a certain buoyancy; Sun protection.

Extended data:

Dangers and injuries of free diving:

1, air pressure injury leads to perforation of eardrum and congestion of middle ear.

The reason is that the balance of ear pressure is missed, and the eustachian tube is squeezed and blocked. (In the teaching process, first dive by climbing rope, so that students can practice Franz Zoe's pressure balance calmly; Only after students have established a certain sense of ear pressure balance can they begin to teach duck diving. This can easily lead to eardrum tear, hearing loss, otitis media and temporary or long-term deafness.

2. Air pressure injury leads to frontal sinus crush injury, frontal sinus pain and frontal sinus bleeding.

3. Reverse obstruction of middle ear and frontal sinus.

In the real free diving practice, the reverse obstruction of the middle ear is relatively rare, but this does not mean that it is impossible. Reverse obstruction of frontal sinus occurs from time to time. The main reason is the thickening of frontal sinus mucosa caused by cold, inflammation or long-term smoking. When diving, the air that enters the frontal sinus due to extrusion is blocked by thick mucous membrane and mucus when it rises, and cannot be discharged from the frontal sinus, and then expands and squeezes the frontal sinus, causing severe pain.

4. Loss of self-consciousness control caused by hypoxia; Shallow water blackness coma; Deep water dark vision coma; Black vision coma will damage the brain, lead to short-term memory loss and may lead to habitual black vision coma;

5. Lung compression caused by diving depth exceeding residual lung capacity.

Our lungs are used to store air and exchange gases. When diving, the lungs are squeezed and become smaller. When it rises, the air in the lungs will expand.

The lung can't be compressed indefinitely. If it is compressed to a certain extent, it will keep the same volume and can't be compressed any more. This depth is generally around 30-40 meters.

When the lungs are no longer compressed and smaller, if the free diver continues to dive, he will not be able to draw air from the compressed lungs to balance the ear pressure.

At the same time, if you continue diving, the volume and pressure of the lungs will remain unchanged, the pressure of the surrounding environment will increase, and the lungs will form negative pressure, which will pump out the air stored in the mouth.

Baidu encyclopedia-diving suit

People's Network-Safety Precautions for Free Diving