What is the maximum allowable depth for a SCUBA dive when the standby diver has less than 100 SCF of air?

When determining the maximum allowable depth for a SCUBA dive based on the air supply available to a standby diver, guidelines are established to ensure safety in underwater operations. The amount of air is critical because it dictates how long the standby diver can support the primary diver in case of an emergency.

In many diving operations, the standard practice is to limit the depth of dives when the standby diver has less than 100 cubic feet of air (SCF) available. This ensures that there is sufficient air to handle emergencies while considering the increased breathing rate and the pressure change associated with greater depths.

At a depth of 60 feet of seawater (FSW), the total ambient pressure is approximately 2.8 atmospheres, which means that the diver's breathing gas consumption will increase due to the higher pressure. Keeping the maximum depth at 60 FSW allows the standby diver sufficient air reserve and time to assist the primary diver if necessary, while minimizing risk.

This regulation also reflects a commitment to safety, ensuring that standby divers can be effectively deployed if a situation arises. This maximum depth of 60 FSW is a common operational standard in diving practices, particularly when a limited air supply is present.