What to do:

Hold the regulator second stage loosely in your mouth, allowing excess air to escape. If possible, angle your head slightly to avoid bubbles in front of your eyes.

No-nos

• Avoid taking a “test” breath from your regulator in temperatures near freezing. The moisture in the atmosphere and your breath can easily cause icing in the second stage.
• Avoid pressing the purge button.
• Avoid heavy breathing
• Avoid adding air to your BC in small bursts
• Avoid using your regulator for secondary use. While filling up a safety sausage, use your exhaust valve, and if you need to fill a lift bag in cold water, consider using a spare tank for that purpose.

When a regulator suddenly free-flows, it can be very startling as there is a sudden roar of bubbles and visibility is reduced.
The main strategy is to:

• Remain calm: Stop - Think - Act
• If you are confident of breathing from a free flowing regulator do so, but check and prepare alternate sources just in case.
• If an alternate air supply is preferred and available, switch to it.
• Head for the surface.
• If a buddy is available, or you can reach the cylinder valve, switch off the cylinder and slowly switch it back on.
• If you run out of air then the only option is a free ascent, possibly accelerate it by removing the weight belt. Ensure you don’t hold your breath, or the air inside the lungs will expand. ■