What is the positive pressure capability of the MK 20 Mod 0 provided to the Full Face Mask (FFM)?

The positive pressure capability of the MK 20 Mod 0 is designed to ensure that the Full Face Mask (FFM) maintains a slight positive pressure relative to the ambient water pressure. This is essential for underwater diving as it helps prevent water from entering the mask, providing the diver with a safe and dry breathing environment.

The correct answer, which indicates a positive pressure capability of 0.03 PSI, reflects the specifications necessary for this type of diving equipment. This level of positive pressure allows the gas within the mask to be higher than the pressure outside, thus keeping water at bay and ensuring the diver's comfort and safety.

This choice is pivotal as it represents a balance between ensuring safety and practicality for the diver, maintaining a secure fit without significantly adding resistance to a diver’s breathing effort. Understanding this parameter is crucial for divers operating under various conditions, especially where ambient pressure can change significantly.