SDI Open Water Scuba Diver Practice Exam 2025 - Free Scuba Diver Practice Questions and Study Guide

The piece of equipment that should never be allowed to dangle freely during a dive is the alternative air source. This equipment is crucial for emergency situations, where a diver may need to share air with a buddy or may need to access an additional air supply themselves. If it is dangling and not secured, it could become tangled in other gear or environmental hazards, creating potential risks during a dive. Ensuring that the alternative air source is properly stowed or stowed in a way that allows for quick access prevents such issues and enhances safety.

While other pieces of equipment, such as the BCD, weight belt, or dive computer, have their own importance and risks associated with being unsecured, the alternative air source stands out because it is directly tied to emergency protocols. A malfunction or difficulty in accessing this critical equipment could have serious consequences underwater. Thus, it is essential to keep alternative air sources neatly secured and immediately accessible during a dive.