Doubles Hose Routing: What Goes on Each Post and Why

You're kitting up on the boat. Your doubles sit on the bench next to your teammate's. Picture their left post. You already know what's on it.

You know without looking.

That's the whole idea. A doubles rig can be plumbed a hundred ways, and most of them work fine. Right up until something fails. Then the only layout that matters is the one you, and your team, can work with your eyes closed.

What goes on each post?

Two posts. Five hoses. Nothing extra.

Why split it this way?

Here's the thing. Doubles aren't really about more gas. They're about options when something breaks.

Two cylinders, joined by an isolator manifold, each with its own first stage. If one side fails, you shut it down and keep diving on the other while your team ends the dive. The layout decides what you still have when you do.

Lose the right post. Your long hose and wing inflator are gone. You switch to your backup, on the left. Your drysuit still takes gas from the left, and your wing still has its oral inflator.

Lose the left post. Your backup, gauge and suit inflation are gone. You still have your long hose to breathe and your wing to add lift.

Either way: one regulator to breathe, one way to add buoyancy. That's not an accident. It's the design.

There's a second reason, and it lives on the ceiling. Drag the left valve knob along an overhead and it tends to turn toward closed. That's a roll-off, and a left-post roll-off is one of the failures UTD teams train for. Drag the right knob and it tends to turn open. So the wing goes on the post that stays on.

How does each hose route?

Right post

The long hose. It leaves the right first stage and drops straight down your right side. At your hip, it's retained under your light canister or tucked into your waist belt. Then it runs up across your chest, around the back of your neck, and into your mouth from the right. When you donate, it presents straight to your teammate. The full routing is in Long Hose Configuration.

The wing inflator. It comes up off the right first stage and crosses behind your head to the inflator on your left shoulder. Keep it close. It shouldn't stand up in a loop above your valves where it can catch a line or an overhead. Wing Inflator Hose Routing covers it in detail.

Left post

The necklace backup. Over your left shoulder to the bungee loop under your chin. You take it with your left hand the moment your long hose leaves your mouth. See Bungeed Backup Regulator.

The pressure gauge. Down your left side to the left hip D-ring. Short enough that nothing dangles. Long enough that you can read it without unclipping it.

The drysuit inflator. Under your left arm to the suit valve. If you breathe helium, you'll probably feed the suit from a separate inflation bottle instead.

What goes wrong?

Let's be honest. Most people don't build a messy rig on purpose. They build it one hose at a time, the way it fit that day.

The comfortable belief: it's my rig, so I'll set it up the way I like.

The truth: your rig is your team's rig too. When your teammate reaches for your left post in the dark, it had better be where theirs is.

Here's what I'd look for first:

• Wing and drysuit on the same post. Lose that post and you lose both ways to add gas.
• Inflator on the left post. It works. Until the left post rolls off against a ceiling.
• A gauge hose that's too long. The gauge swings below you, drags and collects silt.
• A long hose trapped under other gear. It has to come free in one movement.
• Hoses that stand proud of your outline. Every loop is a snag point.

DIR Hose Lengths has the typical length for every hose on the rig.

A five-point check before you get wet

1. Right post: long hose and wing inflator. Nothing else.
2. Left post: backup, gauge and, if you're dry, drysuit inflator.
3. Outline: no hose loops past your silhouette, from behind or from the side.
4. Reach: you can reach both posts and the isolator. If you can't, you can't do a valve drill.
5. Function: breathe each regulator while you watch the gauge. Inflate the wing. Inflate the suit.

Simple. Every dive.

Can you name every hose?

Go look at your rig. Right post. Left post. Can you name every hose without looking? Can your teammate? Could you shut down either side, by feel, and know exactly what you just lost?

If the answer is "not yet," that's what the Doubles course is for. Bring your rig. We'll build it right.