What is the minimum cylinder size recommended for deep dives?

The recommendation for a minimum cylinder size of 12 liters (71.2 cubic feet) or larger for deep dives is based on the increased air consumption that occurs at greater depths. As divers go deeper, the pressure increases, which affects how quickly air is consumed. A larger cylinder allows for an adequate volume of air to ensure that divers can complete their dive safely while taking into account the increased breathing rate at depth.

Using a smaller cylinder may result in insufficient air supply for the planned dive profile, increasing the risk of running low on air and potentially leading to an unsafe situation. This is particularly important for deep dives where the potential for longer ascent times or safety stops exists. Therefore, having a 12-liter cylinder or larger provides a better safety margin and accommodates the air consumption required for deeper dives, making it a practical choice for advanced diving.