What defines a buoy-style oxygen regulator, and what role does it serve in scuba diving?

A buoy-style oxygen regulator, also known as a stage regulator, is a specialized type of scuba diving regulator designed for use with enriched air or nitrox blends. It serves a specific role in scuba diving by allowing divers to breathe gas mixtures with higher oxygen concentrations than the typical compressed air used in recreational diving, which is about 21% oxygen and 79% nitrogen.
Here are the key features and functions of a buoy-style oxygen regulator:
Dedicated Use: A buoy-style oxygen regulator is designated for use with nitrox or other high-oxygen content gases. It is not used for breathing regular compressed air because the materials used in its construction are not suitable for high-oxygen environments.
High Oxygen Compatibility: These regulators are specially designed to handle the higher oxygen levels found in nitrox mixes, typically containing 32% to 40% oxygen or even higher. They are constructed using materials that are compatible with oxygen-rich gas to reduce the risk of combustion or fire.
Separate Cylinder: Typically, divers use a buoy-style oxygen regulator with a separate cylinder (often called a "stage" or "deco" cylinder) containing the nitrox mix. This cylinder is not connected to the primary breathing gas supply and is used for specific purposes, such as extended bottom times or decompression stops.
Adjustable: Like standard regulators, a buoy-style oxygen regulator is adjustable, allowing divers to control the flow of gas to match their breathing needs and depths.
Compact and Lightweight: These regulators are often more compact and lighter than primary regulators, making them suitable for use as secondary breathing devices in specific diving situations.
Purpose: Buoy-style oxygen regulators are primarily used for decompression diving, where divers use nitrox blends to reduce the risk of decompression sickness and extend bottom times. They are also used for safety stops, accelerated decompression, or when a specific gas mix is required for a particular stage of the dive.
In summary, a buoy-style oxygen regulator is a specialized scuba diving regulator designed for use with high-oxygen content gases like nitrox. It is primarily used in decompression diving and other specific situations where customized gas blends are required to enhance safety and dive flexibility. These regulators are not used for breathing standard compressed air and are distinct from primary regulators used for that purpose.