What is the recommended spacing between the main line and belay system?

The recommended spacing between the main line and the belay system is intended to optimize both safety and operational efficiency during a rescue operation. Keeping the lines close enough prevents a pendulum effect, which can occur if the two systems are widely separated. A pendulum effect could lead to uncontrolled swings, making it difficult for rescue personnel to manage the load and positioning of the victim or rescuer on the main line.

At the same time, it is crucial that the two systems are not so close as to interfere with each other's operations. If the main line and belay system are too close, rigging issues can arise, creating potential hazards. Therefore, the correct spacing allows for effective functioning of both systems while minimizing the risk of complications during rescue efforts.

While some of the other choices suggest specific distances or approaches to spacing, they do not account for the operational dynamics involved in rescue scenarios. The ideal spacing should balance safety concerns with practical considerations, leading to the conclusion that the best approach is to maintain a close but non-intrusive distance between the main line and belay system.