Second, the difference between free diving, scuba diving and snorkeling

There are three types of diving in the broad sense: free diving, scuba diving, and snorkeling.

Free-diving

It refers to a sport that does not carry an air bottle and that only uses its own lung capacity to adjust its breath-hold gas as far as possible. Due to the dangers and the high transparency of the open waters of the sea (appropriate dive sites) suitable for practice, the practitioners and their potential companions should be equipped with professional first aid knowledge and other reasons. Since the 1970s, this sport has only As underwater extreme sports, it has not been widely promoted to the public. Today's free diving also has new developments. The World Free Dive Association was established - AIDA. Each year AIDA will hold a free diving competition.

Scuba diving SCUBADIVING (SCUBA:Self-ContainedUnderwaterBreathingApparatus)

Scuba diving is the use of compressed air bottles (not many people think that use oxygen cylinders), using underwater breathing apparatus to breathe underwater, is a real dive into the underwater diving. The full range of scuba diving equipment includes masks, breathing tubes, ankles, breathing apparatus, diving instruments, gas cylinders, buoyancy adjusting vests and diving suits. Divers will also carry diving knives, underwater flashlights and even spears when diving in open waters. And other necessary auxiliary equipment. Among them are open-circuit breathing systems and closed-circuit breathing systems. The principle is to use a regulator device to convert the compressed gas in the cylinder into a pressure that can be normally breathed by the human body. The open respiratory system is relatively simple and it is also a system that is used by more people nowadays. Such a system supplies breathing gas to the diver for single use and is discharged.

Closed breathing system, also known as rebreather, provides reusable air supply. After the diver uses the gas supply, the system will absorb the carbon dioxide and re-inject the appropriate oxygen and supply it to the diver. Such systems can provide compressed air, Nitrox, or a variety of gas mixtures for divers. Different gases can be used to target different time and depth of dive to avoid decompression sickness (commonly known as divers or cages) or oxygen poisoning (Oxygen Toxicity).

Scuba diving is also generally divided into Recreational Diving, Technical Diving, and Commercial Diving. Recreational diving refers to viewing recreational diving activities, usually not more than 40 meters deep. Technical diving refers challenging diving activities, such as large depth of diving, underwater caves, wreck diving and other activities. Industrial diving refers to diving activities of industrial nature, such as underwater engineering and shipbuilding.

Snorkeling

It is relatively simple, just use the mask, breathing tube and ankle to float on the water, and then watch the underwater landscape through the mirror, and the observation will not be interfered by the blisters. Snorkeling is a very popular leisure activity in tropical resorts and scuba diving areas. The snorkeling activities can be carried out at home and abroad as long as the training is simple and it is not necessary to obtain a snorkeling certificate.