Power inflator hoses should run over the diver's left shoulder and be long enough to comfortably supply the power inflator, while not so long that they bulge out to either side. In turn, the inflator itself should be long enough that, with one hand controlling all maneuvers, a diver is able to easily reach his/her mouth, his/her dry suit inflation valve, and his/her nose; it should also be long enough that, if necessary, one could breathe out of it by simultaneously holding down both buttons.13 The inflator from the wings runs over the shoulder and through a small bungie attached with the left chest D-ring. This keeps the inflator where it can be located instantly. To provide additional redundancy when using two first stages, the inflator hose should always be run from the right post. This requirement is illustrated in the case of a diver's left post rolling off or breaking. If the inflator is run from the left post, the diver will simultaneously lose not only the use of the backup regulator around the neck but also the ability to inflate the BC. These two problems together could be inordinately compounded by an out-of-air situation in which a diver would not only be without the means of controlling his/her buoyancy but would also be deprived of the use of a third regulator (cf. note 7). In addition, the inflator mechanism itself should not be designed to fill rapidly; this allows one to manage a runaway inflation more effectively, should an inflator failure cause a continual addition of air. The pressure gauge hose should run from the diver's left post to the left hip D-ring, where it is attached by a stainless steel clip wire-tied to the pressure gauge. This pressure gauge does not need a protective boot, nor does it need to be in a console or in any other device that increases its size and/or entanglement potential. The hose should be short enough to stay out of the slipstream and long enough to allow for viewing of the gauge once it is unclipped from the D-ring.
Regulator Configuration
Diving With One First Stage
Shallow, open water divers often use one first stage attached to a single tank. With a single regulator, the two-second stages come over the diver's right shoulder while the pressure gauge and power inflator run to the left.
Diving With Two First Stages
Divers use double tanks for technical diving not only because they seek to increase their available air supply, but also because they understand the safety margin provided by redundancy. Therefore, the use of double tanks usually indicates deeper or overhead diving. Both single tank diver and double tank diver systems require the following configuration. Open water divers using a single tank should assume that all necessary hoses run from one first stage. In a doubles configuration, the primary second stage regulator is attached via a long hose to a first stage that is affixed to the diver's right post (right shoulder). This configuration not only ensures redundancy, but also facilitates gas sharing. The long hose runs straight down behind the wing, under the light canister (if one is worn, if not it is routed around the knife, or tucked into the belt), back up the left side, and around the neck; the attached second stage is then placed in one's mouth and breathed. During an emergency air-sharing episode, divers will have to unclip this regulator to pass it to an out-of-air diver. While using stage or deco bottles, donors should pass the regulator in their mouth (stage or deco) and then deploy the long hose. Should the out-of-air diver need additional decompression gas, the divers will likely take turns using the bottle (such as five minutes each) or buddy-breathe. Out-of-air divers should also be practiced in going directly to the long hose, and be able to breathe from it while it is still clipped off, deploying it later without assistance. Divers must also practice quickly deploying the long hose in a variety of situations.
Divers should NEVER put their primary regulator on the left post because they risk a post roll off during contact with an overhead. Furthermore, severe contact might cause this knob to be severed in the off position, leaving the diver without a long hose in case of an emergency. Placing the long hose on the diver's right post means that the post can only be rolled open, and, in the case of a broken knob, will still be usable (both knobs turn clockwise but are on opposing sides). As with any new technique, divers may notice an early learning curve. However, a couple of dives should be sufficient for them to become proficient in managing a long hose. Whenever it is not in use divers should become habituated to clipping off their long hose to their right D-ring. While diving, hoses generally float and sit comfortably against one's body. Since, for purposes of gas exchange and general good form a diver should always be in a supine position, this long hose will usually be held in place against the body.
Does the Long Hose Decrease Regulator Performance?
Regulators can easily supply air through a long hose without registering any notable drop in breathing performance. If there is any reduction in regulator performance when using the long hose, it is negligible, and in all but the lowest performance regulators, not even a noteworthy concern. If being attached to a long hose diminishes a regulator's performance, then the regulator itself is not suitable for normal diving use.
Gauges
Historically, divers have been led to believe that consolidating an array of gauges into one bulky console and then dragging that console along behind them was somehow a sensible and responsible practice. Not true. By dragging a bulky console behind them, divers not only kill whatever coral they come in contact with, they also risk entanglement. Instead, divers should wear their depth gauge and compass on their wrist or forearm. In the ocean, a compass is of paramount importance, and, without interfering with other activities, needs to be viewable and held in its correct orientation on the left hand. The bottom timer/depth gauge needs to be viewable at all times and should be placed on the right hand.