The greatest help of sea lions to mankind is to dive to the bottom of the sea for people to salvage what has sunk into the bottom of the sea. Since ancient times, when an object sinks into the ocean, it means that nothing can return. But today, with the development of science, some valuable experimental materials must be recovered, such as satellites that return to Earth from space and splash into the ocean, and objects that splash into the ocean from launch tests. When the water depth exceeds a certain limit, divers can do nothing. However, the sea lion has superb diving skills, and people turn to it to complete some diving tasks, which can replace divers to salvage underwater relics, conduct underwater military reconnaissance and save lives. For example, a well-trained sea lion in the US special forces picked up a rocket that sank into the sea in 1 minute, but people only paid him a little squid and fish.

California sea lions, distributed in the waters south of Mexico and California, can be tamed and used for military purposes. It is also often domesticated by zoos and aquariums to perform and become people's favorite performance star.