The purpose of using a spotter is to assist:

Using a spotter serves the important purpose of assisting the driver by observing the area in the blind spot. When maneuvering large fire apparatus, visibility can be severely limited, particularly around the rear and sides of the vehicle. A spotter can provide real-time feedback to the driver, helping them navigate safely by alerting them to obstacles, pedestrians, or other vehicles that may not be visible through mirrors. This additional set of eyes is crucial for preventing accidents and ensuring a safe response, especially in environments with limited visibility. The coordination between the driver and the spotter enhances overall safety and operational effectiveness during fireground operations or while navigating through chaotic situations.