It seems hard to talk about the exactly prevailing time of recreational diving all over the world, people’s yearning for the sea and the unknown seabed exploration activities are more and more frequent with the development of science and technology. Like the protagonist of the film "blue sky", which directed by the famous director Luc Besson, was eager to dive into the deep blue sea, and eager to get close with nature. However, due to limitations of the human physique, we can not dive into the seabed the same as the fishes and travel freely without the help of diving equipment. Because the underwater pressure will cause great oppression to human beings’ cardiopulmonary and the oppression will be greater with the increasing depth.

 

When you finished the diving equipment wearing and went into the sea, the weight of your own body and the weight of diving equipment can only let you dive to a certain depth, if you want to continue to dive, it will suffer from resistance generated by the underwater pressure. How to overcome this pressure to make their own can freely adjust the diving depth? The answer is the counterweights. Early recreational diving counterweights were mostly made of lead, but the toxic properties of lead would pollute the sea, which is not the situations that people want to see. Thus, non-toxic and environmental characteristics of tungsten alloy make it a good alternative to lead recreational diving and has become special material for recreational diving counterweights.