What must an Incident Safety Officer (ISO) ensure at a water rescue incident?

In the context of a water rescue incident, it is crucial for the Incident Safety Officer (ISO) to prioritize the safety protocols set in place for responders. The correct answer highlights the necessity for all responders near the water's edge to wear a personal flotation device (PFD), which is an essential safety measure in a potentially hazardous environment like water rescue.

Wearing a PFD significantly reduces the risk of drowning and enhances the safety of all personnel involved. This is because water environments can be unpredictable, and responders may find themselves in situations where they need additional buoyancy and support. Ensuring that all responders near the water's edge are equipped with PFDs helps to maintain a safe operational area, thus safeguarding the personnel involved in the rescue efforts.

While the other options might sound relevant to some degree, they do not address the immediate safety concerns that PFDs mitigate. For example, the option about having responders enter the operational area before developing the Incident Action Plan (IAP) overlooks the critical need for a structured safety plan. Similarly, limitations regarding personnel on watercraft or Level II responders pertain to situational roles but do not directly impact the immediate safety measures that PFDs provide for all responders near the water's edge.