Trimix is a breathing gas used in deep-sea diving, consisting of three components: oxygen, nitrogen, and helium. The combination helps reduce the risks associated with deep dives, such as nitrogen narcosis and oxygen toxicity, allowing divers to explore greater depths safely. Divers typically adjust the proportions of these gases based on the depth and duration of the dive. Helium is included to replace some of the nitrogen, which can cause narcosis at high pressures. By using Trimix, divers can extend their time underwater while minimizing potential health risks.