Single Tank Regulator Setup: DIR Hose Routing on One First Stage

On a single tank, one first stage does everything. The long-hose primary leaves a right-side port and runs down your right side. The necklace backup, wing inflator and pressure gauge leave the left. A drysuit hose takes whichever spare low-pressure port gives it the cleanest run. It's the doubles layout, scaled down.

By Jeremiah Gardner · Last reviewed October 17, 2026

Look at a typical rental regulator. A yellow octopus on a long loop. A console swinging off the side. Hoses pointing every direction.

It works. Until you need it to work fast.

The problem isn't the gear. It's that nothing lives in a fixed place. And a regulator you have to look for is a regulator you can't count on.

What does the single tank layout look like?

One first stage. Five hoses. Every one of them has a job and a place.

Hose	Side	Where it goes	Typical length
Long-hose primary	Right	Down your right side, retained at the hip, around your neck	7 ft (UTD allows 5 or 7)
Necklace backup	Left	Over your left shoulder to the necklace under your chin	About 22 in
Wing inflator	Left	Up to the inflator on your left shoulder	Supplied with the wing
Pressure gauge	Left	Down your left side to the left hip D-ring	About 26 in
Drysuit inflator	Either	Under your arm to the suit valve	Short, fitted to the rig

Off-the-shelf single tank hose kits look exactly like that: a 7-foot primary, a 22-inch backup and a 26-inch gauge hose (example kit). Gardner Underwater's equipment list specifies the 7-foot primary.

How should each hose run?

Set the first stage first. Mount it so the long hose port faces your right side and every hose can leave without a sharp bend. Many first stages have a swivel turret that makes this easy. On fixed-port first stages, pick ports by where each hose needs to go, not by which port is closest.

The long hose. Right-side port. It drops straight down your right side, gets retained under your light canister or tucked in your waist belt at the hip, crosses your chest and wraps around your neck into your mouth from the right. That's the regulator you donate. Long Hose Configuration walks through the donation.

The backup. Left-side port, over your left shoulder, held under your chin by a bungee necklace. Because its hose arrives from the left, the second stage may need to be set up for left-side routing. Ask your regulator technician. See Bungeed Backup Regulator.

The wing inflator. Left-side port, straight up to the inflator on your left shoulder. No loop over the top of the valve.

The pressure gauge. High-pressure port, down your left side, clipped to the left hip D-ring. You should read it without unclipping it.

The drysuit hose. A spare low-pressure port. Which side depends on your first stage. What matters is the result: a short run under your arm to the suit valve, close to your body, with nothing looping out.

Why does the long hose go on the right?

Because of what happens next.

You take the regulator out of your mouth and hand it to a teammate who's out of gas. It comes in from the right, so it presents straight to them, right way up. Your left hand goes to your chin. Your backup is there. You breathe.

The whole layout is built around those few seconds. Right hand donates. Left hand finds the backup. Everything else stays out of the way.

Is this overkill on a single tank?

Let's be honest. A lot of divers think DIR routing is for tech divers. Doubles. Caves. Not a Saturday at La Jolla Shores.

The comfortable belief: I'm a recreational diver, so a recreational setup is fine.

The truth: an out-of-gas emergency doesn't check your certification card first.

And here's the part people miss. The single tank is where you build the habit. The layout you learn on one first stage is the one you'll use on doubles, with stages and on a scooter. Learn it once. Then just keep adding. DIR for Recreational Divers makes the case in full.

What should you check before every dive?

Long hose on the right, free to deploy in one movement.
Backup under your chin, not hanging at your chest.
Gauge clipped at the left hip, readable without unclipping.
Inflator connected and working.
No loops standing out from your outline, front or back.
Breathe both regulators while you watch the gauge.

Pre-Dive Checks covers the full routine.

Can you set it up from memory?

Pull your regulator out of the bag tonight. Lay it on the floor. Where does each hose go? Why there? Which hand reaches for which regulator, and when?

If you can answer all of that without thinking, good. If you can't, start with Essentials of Recreational Diving. It's where the layout stops being a picture and becomes a habit.

Frequently asked questions

Which side does the long hose come off on a single tank?

The right. It leaves a right-side port and drops straight down your right side, so it can be retained at the hip and wrapped around your neck into your mouth from the right.

Where does the backup regulator go on a single tank?

On a left-side port, routed over your left shoulder to a bungee necklace under your chin. Its second stage may need to be set up for a hose coming from the left.

Which side should the drysuit hose go on with a single tank?

It depends on your first stage. Use the spare low-pressure port that gives the shortest, cleanest run under your arm to the suit valve, with no loop.

What hose lengths does a single tank DIR setup use?

A typical kit is a 7-foot long hose, a 22-inch backup hose and a 26-inch pressure gauge hose, plus the inflator hose supplied with your wing.