What does "Lay a Line" refer to in firefighting?

"Lay a Line" in firefighting specifically refers to the action of connecting a fire hose to a fire hydrant. This is a crucial step in ensuring that firefighters have a reliable water supply when responding to a fire. By connecting the fire hose to a hydrant, firefighters can deliver the necessary water to combat the flames effectively.

This task is fundamental to fire operations because inadequate water supply can severely hinder firefighting efforts. The process often involves deploying hoses from a vehicle to the hydrant, ensuring that the connection is secure and that water can flow without interruptions. The efficiency of this action can greatly influence the outcome of firefighting efforts in an emergency situation.

In contrast, the other options involve different aspects of firefighting procedures. Connecting hoses to a fire hose reel pertains to equipment management, establishing a communication link is related to coordination among team members, and mapping the area of operation is essential for planning but does not directly involve the water supply needed for extinguishing fires. Thus, "Lay a Line" distinctly pertains to the vital connection between the hose and the hydrant, making it the correct choice.