Which buckle should guests be instructed to buckle themselves?

Guests should be instructed to buckle themselves with the sternum buckle because it plays a crucial role in securing the harness system to ensure safety during activities that involve elevation or movement, such as in urban air environments. The sternum buckle connects the upper part of the harness across the chest, which helps to keep the shoulder straps in place and prevents them from slipping off during operations.

This is particularly important as it provides an additional layer of restraint, helping to distribute forces in the event of a sudden stop or change in direction, thereby enhancing the overall safety of the guests. Securing the sternum buckle also assists in maintaining proper posture, ensuring that the body remains aligned and stable. Thus, instructing guests to secure their sternum buckle is a key safety measure that helps mitigate risks associated with the activities they are engaging in.