What is the preferred knot for tying a main line to a litter?

The bowline on a coil is favored for tying a main line to a litter due to its reliability and security. This knot creates a fixed loop at the end of the rope, which can easily be attached to the litter while still allowing for a secure fit that won't slip under load. The structure of the bowline allows for easy untie after it has been loaded, making it especially useful in rescue situations where the knot may need to be undone quickly after being loaded.

This knot's effectiveness in maintaining its strength and stability under tension is essential in rescue scenarios to ensure the safety of both the victim being transported as well as the rescuers. The bowline on a coil option also provides versatility, allowing for quick adjustments to the loop size and ease of tying without needing to remove the coil of rope from the person’s body.

Other knots mentioned may not provide the same level of security or functionality when it comes to this specific application, making the bowline on a coil the preferred choice.