What type of knot is used as a substitute for a boatswain's chair?

The Spanish bowline is an advantageous choice as a substitute for a boatswain's chair due to its unique structure and versatility. This knot creates a fixed loop at the end, which can safely secure a person during operations at heights, much like a boatswain's chair. Its design allows for easy adjustment while providing a stable and secure hold, ensuring safety for crew members who may be working aloft.

In maritime applications, the Spanish bowline is particularly valued for its ability to untie easily even after bearing substantial weight, making it reliable for lifting and securing individuals. It is a double-loop knot, which adds to its strength and stability, enhancing its suitability for personnel movement in a safe manner.

Other types of knots, while useful in various contexts, do not provide the same level of safety and functionality for this specific purpose as the Spanish bowline. For instance, the monkey fist is primarily an ornamental knot or for throwing and does not serve for secure sitting or lifting. The mast head knot pertains to rigging and securing sails rather than safe personnel handling. The black wall hitch is suited for securing lines to posts or rings but lacks the necessary design to safely accommodate a person in the same way a boatswain's chair does.