Hardware

• 1 1^st stage regulators
• 2 2nd stage regulators
• 1 submersible pressure gauge (spg)
• 1 5-7' LP primary regulator hose
• 1 22-24" LP backup/secondary regulator hose
• 1 26" HP SPG hose
• 1 appropriate length low pressure inflator (lpi) hose
• 1 appropriate length drysuit inflator hose

Orientation

When discussing the orientation of the tanks and hoses, we speak in terms of how the tanks are oriented to the diver, while wearing the tanks. 

The primary and backup 2nd stage hoses are attached to the right side of the 1st stage, meaning the right side of the 1st stage when the diver is wearing the tank.

The hp (high pressure) SPG (Submersible Pressure Gauge) hose, lpi (low pressure inflator, or wing inflator) hose and drysuit inflator hose or "whip" are attached to the left side of the 1st stage, when worn.

When connecting the hoses, all connections should be slightly tighter than finger tight.  Be careful not to use excessive torque when tightening the hose to the 1st stage, 2nd stages or SPG.  A slight nudge of a wrench beyond finger tight is plenty.

Right Side

The primary regulator is the reg the diver breathes from during the dive.  It is also the regulator that is donated to an out of gas (OOG) diver.  In the event of an out of gas situation, the donor donates the regulator he/she is breathing.  This ensures the out of gas diver receives a known working regulator with a gas that is breathable at that depth.  

In open water, non-overhead environments, it allows the divers the flexibility to facilitate a side-by-side direct or swimming ascent, or a face-to-face direct ascent, as needed.  To enable this, the primary regulator typically has a 5-7' hose (7' for overhead environment) "longhose".

When geared up (pictured below), the diver routes the longhose (illustrated in yellow) from the right side down behind, under the light canister, around the waist and up across the chest and around the left side of the neck and into the diver’s mouth.  The excess of the hose is stowed behind the light canister or, if no canister, tucked into the waist strap or under the knife sheath.  

The backup regulator's hose (illustrated in red) is typically 22-24" and is routed over the diver's right shoulder.  The length of the backup hose must be long enough to allow the regulator to rest under the diver's chin when not in use and allow enough freedom of movement to fully turn and look to the left when in use.  However, if the hose is too long, it will rest over the right chest D-ring, making it difficult to attach or deploy equipment from that D-ring and/or may possibly trap the hose as equipment is attached to the D-ring, over the hose.

Left Side

The low pressure inflator, or lpi (illustrated in blue), is connected to the left side of the 1st stage and is routed along the corrugated hose via bicycle inner-tube, and connects to the inflator mechanism.  The length of the lpi hose will vary depending on the length of the wing’s corrugated hose.  The lpi hose length should be such that it's not too long, where it has a large “loop”, or “pushes” the corrugated hose down, nor too short, “pulling” the corrugated hose up. 

The drysuit hose length (illustrated in green) is as needed so as it does not restrict the diver’s movement, nor does the hose form a “loop” causing unnecessary entanglement hazards or clutter.  It should be routed from the left side of the 1st stage, under the diver’s left arm and shoulder harness. 

The spg is connected to the high pressure (HP) port of the 1st stage.  The spg/HP hose (illustrated in black) is typically 24-26”.  It must be long enough to allow the spg to sit over the left hip D-ring, but no so long that it bulges out or allows the spg to dangle below the diver. 

Result

Now that we've covered each hose individually, let's look at how it functions together.

In this picture:

Right Side

- 7'  primary regulator longhose (yellow)

- 22-24"" LP backup/secondary regulator hose (red) 

Left Side

- 17" lpi hose (blue) connected to a 13" corrugated hose 

- 26" hp SPG hose (black) 

- 26" drysuit inflator hose (green)

Note the clean hose routing.  Also note the lack of hose protectors on all hoses.  There are no large bends where the hose comes off the 1st stage.

Right Side View - Geared Up

In this picture:

- Right side

- 7' LP primary regulator "longhose" (yellow)

- 24" LP backup regulator hose (red)

- Light canister

Note how the primary regulator longhose (yellow), is connected to the right side of the 1st stage and routed down, and under the light canister.  When geared up, the diver routes the longhose (illustrated in yellow) from the right right side of the 1st stage, under the light canister, around the waist and up across the chest.  It then goes over the left shoulder, behind the neck and over his right shoulder and into the diver’s mouth.  The excess of the hose is stowed behind the light canister or, if no canister, tucked into the waist strap or under the knife sheath.  Some wings' construction may require you to route the hose over or in front of the wing.  This keeps the 7' hose clean and tight, with no large loops or bulges. This is also the 2^nd stage the diver breathes from during the dive and donates in an OOG emergency.  

Left Side - Geared Up

In this picture:

- Left side

- 17" lpi hose (blue) connected to a 13" corrugated hose 

- 26" LP drysuit inflator hose (green)

- 26" HP SPG hose (black)

- 7' LP primary regulator "longhose" (yellow)

Note how the lpi/wing inflator hose routes from the left side, along the wing's corrugated hose.  It is held in place along the corrugated hose with a bicycle inner tube.

The drysuit inflator hose (silver) routes from the left side, under the diver's left arm and under the left shoulder harness.  There are no loops are bulges, keeping the inflator tight and clean under the diver's armpit, eliminating entanglement hazards.

The HP spg hose (black) is routed from the left side and straight down, where the spg is clipped to the diver's left waist d-ring.  This keeps the HP hose clean, with no bulges or loops.

Front View - Geared Up

In this picture:

- 7' LP primary regulator "longhose" (yellow)

- 24" LP backup regulator hose (red)

- 26" LP drysuit inflator (green)

- 26" HP SPG hose (black)

- 17" lpi hose (blue) connected to a 13" corrugated hose

Note the 7' LP primary regulator longhose (yellow) comes from under the light canister across the diver's torso (over the drysuit inflator hose), over his left shoulder, behind his neck and over his right shoulder to the primary 2^nd stage.  This is the 2^nd stage the diver breathes from during the dive and donates in an OOG emergency.   Note the diver turning his head to the left, ensuring he has adequate slack to turn his head fully.

Also note the 24" LP backup/secondary regulator hose (red) comes over the diver's right shoulder and is held in place via a bungee'd necklace.

The LP drysuit inflator hose (green) is routed under the diver's left arm and is connected to the drysuit inflator mechanism.  Note the importance of connecting the drysuit inflator hose prior to donning the 7' longhose, to avoid "trapping" the longhose under the drysuit hose, preventing full deployment of the longhose to an OOG diver.

The low pressure inflator hose (blue) is connected to the wing's inflator mechanism.  

The 24" HP spg hose is routed behind the diver's left shoulder and is clipped to the left waist d-ring.