What is the maximum overbottom pressure required from 61-130 FSW when diving the KM37?

In underwater diving, especially when using systems like the KM-37, the concept of overbottom pressure is crucial for ensuring the safety and efficiency of the dive operation. When diving to depths within the range of 61 to 130 feet of seawater (FSW), the diver must account for both the ambient pressure and the additional pressure created by any surface-supplied systems in use.

The maximum overbottom pressure required is determined by the total pressure that the system must support at those depths. In the specified range of 61-130 FSW, the ambient pressure can be calculated using the relationship that every 33 FSW of seawater equates to approximately 14.7 psi (atmospheric pressure).

Therefore, at 130 FSW, the total ambient pressure would be about 130/33 * 14.7 psi, which is around 56 psi. To maintain safe operations and ensure reliable breathing gas delivery, the surface-supplied system requires booster or supply pressures that can adequately handle this demand, which accounts for both the overbottom and additional operational pressures.

In this context, 165 psi is recognized as the maximum overbottom pressure for the KM-37 system when diving within the mentioned depth range. This figure