The origins of diving can be traced back to more than 2,500 years when a diver named Scyllis conducted a commercial dive. An ancient Greek historian named Herodotus recorded the 5th century BC, the Persian king Xerxes, who hired Sillis to dive to sink the sunken treasure. Such early dive generally occurs in shallow water areas, which are not more than 30 meters deep and are usually for commercial or military needs. Even if this is not the case, our infinite desire to understand the unknown will also the urgency to sneak into the deep blue.
China has the most abundant karst landform environment in the world, and it also attracts the attention of these cave dive experts. In the last 10 years or so, Chinese cave diving has also begun. The small caves in Beijing, Guangdong, Guangxi, Chongqing, and other places have been surveyed by diving. Although almost no underwater passages have been opened, and the exploration methods are not standardized, some are beautiful. The underwater caves have begun to attract more people's attention.
In 2009, JJ and Casey led the GUE diving team and participated in the Sanmen Seawater Exploration Project in Fengshan, Guangxi. They shipped a lot of diving equipment to China, including underwater propulsion and two Halcyon RB80 rebreathers. Nearly 20 divers from eight countries, including Chinese divers, participated. In February 2009, the diving team opened the underwater passage from the third to the fourth sunroof. In December 2009, during the fourth trip to Sanmenhai, the underwater passage from the fourth sunroof to the fifth skylight was opened, and the maximum depth of dive reached 94 meters.
The Deep Dive team at the 4th Skylight was composed of French Chris and Fred of Canada, using the RB80 rebreather. The lower space of the fourth skylight is very large. In the case of low visibility, after a long period of exploration, the underwater passage was found. JJ even described it as a groping, Chris and Fred from more than 90 meters. The depth gradually rises to 50 meters and merges with the fifth skylight diving team, Australia's Steve and Singapore's Gideon. After signing each other's underwater record book, after several hours of decompression time, return to their respective water inlet points. It also achieved the depth and exploration record of the first Chinese cave diving. Those diving equipment are still kept in Fengshan, Guangxi, waiting for the next diving advancement.