From the exhilarating freedom of breathing underwater to the awe-inspiring sights of marine life, scuba offers countless adventures. But, as with any adventure activity, it’s important to receive proper training, understand the risks, and dive within safe limits to ensure a great experience.

Divers use a combination of essential equipment to explore the ocean: Scuba diving tanks, also known as cylinders, store compressed air or a gas mixture that is carried in the diver’s suit. These cylinders are connected to a regulator that uses a two-stage process to reduce the high pressure of the gas to a breathable level. Scuba divers also wear a vest-like garment, called a buoyancy control device (BCD), to help them manage their weight underwater and on the surface. The scuba diver’s mouthpiece and mask are used to protect the eyes, ears and face from seawater, and fins are worn on the feet to move through the water.

Scientific divers conduct research in the ocean, exploring historical shipwrecks and penetrating underwater caves. Many of these scientists live for extended periods in a pressurized surface habitat, called a saturation system, before being transported under water to work on their projects. In order to perform their jobs, these divers must be decompressed in a timely manner to avoid oxygen toxicity or nitrogen narcosis. Helium-oxygen and other gases can be used to enable deep-diving work without requiring the extended decompression needed with compressed air. Divers use open and closed circuit rebreathers to safely dive with this special gas mixture.