Which of the following is NOT a purpose of the EGS?

The purpose of the Emergency Gas Supply (EGS) in a diving system is primarily to ensure the safety and support of a diver in various scenarios, particularly during emergencies. The EGS serves several critical functions in diving operations.

One of its key roles is to facilitate prolonged underwater exploration by providing an additional supply of breathing gas, which is critical during extended dives. Additionally, in the event of a malfunction or a situation where the diver's primary air supply is compromised, the EGS is vital for providing enough air for safe ascent back to the surface. It also plays a crucial role in emergency situations by offering a reliable backup source of breathing gas to prevent hypoxia or other related incidents.

However, maintaining a constant depth underwater is not a function of the EGS. Depth maintenance is typically managed through other means, such as buoyancy control devices and careful monitoring of descent and ascent rates. The EGS is a supplemental resource aimed at enhancing safety during a dive rather than controlling the diver's depth. Therefore, the option regarding maintaining constant depth does not align with the actual purposes of the EGS, making it the correct choice in this context.