What is the most important rule when assisting a panicked diver?

The most important rule when assisting a panicked diver is to never needlessly endanger yourself. This principle is rooted in the fact that rescuing a panicked diver can be a risky situation and safety should always be the first priority. If a rescuer becomes too involved and endangers their own safety, they can become a second victim, which would complicate the situation further and hinder the rescue effort.

By ensuring one's own safety first, a rescuer can remain in a position to provide effective assistance without compromising their ability to help. Once safety is secured, the rescuer can focus on de-escalating the situation and guiding the panicked diver towards calmness and control.

Other options, while reasonable in certain contexts, do not prioritize safety in the same essential way. Maintaining a safe distance might limit the ability to provide necessary assistance; cutting lines could be inappropriate and dangerous in many scenarios; and attempting to control a panicked diver without ensuring your own safety could result in unintended consequences. Thus, prioritizing the rescuer's safety is fundamental to effectively managing a rescue situation.