Where Should a Scuba Diver Attach an Alternate Air Source?

diving in the green lake
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An alternate air source should be attached to a diver's body somewhere within the triangle formed by the lower corners of his rib cage and his chin.

Why Is the Location of the Alternate Air Source Regulator Important?

Alternate air sources are standard scuba diving gear and are required for most scuba certification courses. An alternate air source regulator is a back-up mouthpiece and air delivery system carried by a diver in order to allow another diver to breathe from his tank in the unlikely event of an out-of-air emergency.

Attaching the alternate air source in a standard position is important because it allows an out-of-air diver to quickly and easily locate it. A standard alternate air source location also provides additional safety in the event that a diver's primary dive buddy is unavailable. Placing the alternate air source somewhere between the lower corners of the rib cage and the chin ensures that an out-or-air diver will be able to approach any diver under water, even one with whom he is unacquainted, and locate and efficiently secure an alternate air source.

Of course, whenever diving with a new buddy, a diver should review air-sharing procedures and emergency equipment position with his new partner before entering the water. Being comfortable with team emergency protocols and acting as a considerate and attentive dive partner is essential for safe scuba diving.

What Are Some Acceptable Locations for Alternate Air Source Attachment?

An alternate air source should be stowed in a manner that allows a dive buddy to identify and secure it easily.

Here are some common places to stow alternate air sources:

• Attached to the Buoyancy Compensator on the Lower Left-Hand Side
Many buoyancy compensators (BCs) have integrated d-rings on the lower left-hand side of the vest to allow a diver to attach the alternate air source regulator to the BC via a quick-release. This is a useful position for a diver who routes his alternate air source regulator hose over his left shoulder.

• Attached to the Buoyancy Compensator on the Lower Right-Hand Side
This is a less-common position, as the majority of recreational divers route the alternate air source regulator hose over the left shoulder. However, in the case that a diver routes the alternate air source hose over his right shoulder, this is an acceptable attachment point.

• Attached to a Chest D-Ring
Nearly every commercially available BC has integrated chest d-rings on the shoulder straps. These d-rings are an excellent and common attachment point for alternate air sources. Some divers attach alternate air sources to a chest d-ring using quick release gadgets, while others simply fold the alternate air source hose once and slide the resulting loop through the d-ring. As long as the alternate air source may be pulled free quickly, either method is acceptable.

• Slid Into the BC Shoulder Pocket
Some BCs have small, long pockets sewn into the shoulders of the chest straps. A diver may fold the alternate air source hose once and slide the resulting loop into the pocket on the shoulder so that the regulator second stage is still completely free and accessible. This pocket is a common feature on many BCs, and is a good option because using it allows a diver to adjust the length of the hose by choosing where to place the loop, thereby facilitating streamlining.

• Integrated Alternate Air Sources
An integrated alternate air source is a fully-functioning back-up second stage that is combined with the inflation mechanism on a BC's corrugated inflation hose. Underwater, the alternate air source does technically hang between the lower corner's of a diver's rib cage and his chin. Using an integrated alternate air source requires practice, as the donating diver must hand off his primary regulator second stage to the out-of-air diver and switch to the integrated alternate air source on his BC. For this reason, a diver who uses an integrated alternate air source should be sure that the hose on his primary regulator second stage is long enough to easily pass off to a buddy. Whenever one buddy in a dive team uses an integrated alternate air source, both team members should be familiar with the slightly more complicated air sharing procedure.

• Necklace
A diver who uses a long-hose/necklace regulator configuration stows his alternate air source regulator on a flexible necklace, so that the alternate air source hangs just below his chin. In an air-sharing situation, the diver hands off his primary regulator (which is attached to a 5-7 foot "long hose") to the out-of-air diver and breathes from the alternate air source hanging below his chin. Again, this is a less-common equipment configuration in recreational diving. If any member of a dive team uses a long-hose/necklace configuration, both divers should be familiar with the slightly more complicated air-sharing procedure.

Unacceptable Locations for an Alternate Air Source

Any location that does not allow a diver to easily locate and access an alternate air source regulator with one hand is unacceptable. Some common alternate air source stowage errors include:

• Dangling Free
Some divers completely neglect to secure their alternate air sources. This is dangerous for several reasons. A diver who is out-of-air may not be able to find the alternate air source quickly; a dangling alternate air source may turn upside down and free-flow (quickly draining the diver's tank of air); it may be damaged by contact with the environment and not function in an emergency; it may become entangled or snagged on a surface; and it may damage coral or other delicate underwater features. Never leave any dive gear unsecured.

• Inside a Buoyancy Compensator Pocket
An alternate air source must be easily visible (that is why they are usually bright yellow) and easily deployable. Unfortunately, it is not uncommon to see a diver with his alternate air source tucked completely inside his lower BC pocket. While this location may technically fall within the triangle made by the lower corner's of a diver's ribcage and his chin, it is not easy to see or deploy, and is therefore unacceptable.

The Take-Home Message About Alternate Air Source Location

A diver may stow his alternate air source anywhere within the triangle formed by the lower corners of his rib cage and his chin. This allows a diver significant flexibility in choosing an attachment point for his alternate air source, as long as he ensures that it is clearly visible and easily accessible. Divers who use less-common types of alternate air sources, such as integrated alternate air sources and long hose/necklace configurations should be sure that their buddies are familiar with the specialized air-sharing procedures associated with these equipment configurations.