Nowadays, diving has become a very popular leisure sport abroad. The original purpose of diving is underwater survey, salvage, repair and underwater engineering. Later, after it was developed, it gradually became an underwater sport with underwater activities as the main content, in order to achieve the purpose of exercise and entertainment. Diving is also a very difficult extreme sport. Diving refers to the activity of diving underwater with gas cylinders and corresponding breathing devices. Diving is divided into escalator water fee and free water exchange, and water exchange water fee is also divided into leisure diving and technical water exchange. Leisure diving is mainly for leisure, and the technical requirements are not particularly high. It makes many people experience the feeling of diving.
The origin of diving is also very long. As early as 2800 years ago, the Azria Empire appeared. At that time, the purpose of their diving was to attack the enemy in the water. Now, the predecessor of our professional diving appeared in Britain 160 years ago. At that time, a British inventor invented helmet diving, which first appeared in Japan. 1924 began to use glass for diving. With the continuous development of diving, during the Second World War, people developed an air-covered submersible, which used a closed-loop device with an air bottle. Later, the French also developed an air submersible, which was very popular in Europe and America. The invention of various submersibles has also made diving better, and more and more people like diving.
The above contents only represent my personal views. Please forgive me if there is any mistake.