Scuba cylinders are probably the most recognizable piece of scuba equipment. They are capable of storing a large amount of compressed air, and this allows divers to remain underwater for extended periods of time. However, the high pressure of this compressed air presents possible hazards to divers, so a thorough understanding of this important piece of equipment is essential for your safety.

In this lesson, you'll learn about the different types of cylinders available, the valves that open and close the cylinder, and required maintenance procedures.

After this lesson, you will be able to:

• List the two common cylinder materials, and identify each material's advantages.
• Explain the significance of cylinder capacity and pressure.
• Decipher the stamped specifications on a cylinder.
• Identify three common cylinder valves.
• Demonstrate proper cylinder storage.
• State the periodic inspection requirements for cylinders.