The diving knife is defense and tools in the process of performing training and combat tasks. It can assassinate the fierce animals underwater, can cut off about 50mm of wooden sticks, and quickly cut off the wrapping of the mesh rope. Use the rear of the handle to hit the shell sea creature. Although the chance of being stumbled in the bottom of the water is very slim, it is still possible, so the cutting tool should be carried during diving (unless the local law is prohibited). The choice of divers is generally a diving knife or a diving tool with a blade. Generally speaking, these tools are widely used and can be used to pry animals or measurement. In order to resist seawater corrosion, in addition to stainless steel, it is used as material, and titanium is also made of titanium.