What essential equipment is required when using surface supplied diving systems?

The correct answer highlights the critical components required for safe and effective operation of surface supplied diving systems. A diving helmet provides the diver with a breathable environment under water while also protecting the head. The umbilical is a crucial lifeline that supplies air and may include communication lines; it connects the diver to the surface support team for both air supply and ongoing communication throughout the dive. An air compressor is necessary to ensure a consistent and adequate supply of pressurized air to the diver. Lastly, a communication set is vital for maintaining contact between the diver and the surface personnel, allowing for coordination and emergency communication.

The other choices, while they include equipment relevant to various aspects of diving, do not encompass all that is necessary for a surface supplied diving system. Wetsuits and diving weights are more associated with free-diving or scuba diving rather than surface supplied systems, which rely heavily on the umbilical and direct air supply from the surface. A dive computer and submersible vehicle are used in different types of diving operations and are not standard necessities for surface supplied diving. Similarly, tools like a flashlight or safety knife, though useful under certain conditions, do not represent fundamental components of the surface supplied diving system itself.