Stage and Deco Regulator Setup: Hoses, Gauge and Stowing

Gas switch. You pull the regulator off the bottle, purge it, confirm the gas with your teammate and breathe.

Five seconds.

Unless the hose is caught under a band. Or the gauge is flapping somewhere you can't see it. Or the second stage is jammed against the clamp. Then it's thirty seconds of fumbling, in midwater, holding a stop.

The fix isn't more skill. It's a simpler regulator.

What's on a stage or deco regulator?

Almost nothing. That's the point.

• One first stage.
• One second stage on a 40-inch low-pressure hose.
• One compact pressure gauge on a 6-inch high-pressure hose. UTD's guidance prefers a small brass gauge.
• A small bungee loop, about 4 mm, to hold the gauge doubled back against the regulator.

No octopus. No inflator hose. No console.

Why a 40-inch hose?

It has to reach your mouth from a bottle hanging on your left side, with your head turned and your body horizontal. And it has to stow along the bottle without leaving a loop. Forty inches does both.

Longer and you're stuffing slack under the bands. Shorter and it pulls your head toward the bottle while you breathe from it.

Why a 6-inch gauge hose?

Because a gauge on a long hose wanders. A compact gauge on a short hose stays tight against the first stage. Doubled back and held by the bungee loop, it sits where you can read it by tilting the bottle, and it never swings.

You check it at the switch. You check it during the stop. It's always in the same place.

How do you route and stow it?

1. Mount the first stage so the second stage hose leaves toward the bottom of the bottle and the gauge sits close.
2. Run the hose down the bottle, under the inner-tube bands.
3. Loop it back up and tuck the second stage under the top band, mouthpiece ready.
4. Double the gauge back and hold it with the bungee loop.
5. Check the outline. Nothing should stand off the bottle.

The rigging is covered in How to Rig a Stage Bottle.

Stage or deco: what's different?

The layout is the same. The gas isn't.

A deco regulator breathing oxygen or nitrox 50 has to be cleaned and assembled for oxygen service. Talk to your regulator technician before a regulator goes on an oxygen bottle. Don't swap regulators between bottles on the boat just because one is closer.

And the bottle carries its gas on the outside. MOD in big numbers. OXYGEN down the side of an oxygen bottle. See Deco Bottle Marking.

What should you check before the dive?

• Breathe it with the valve open. Watch the gauge. The needle shouldn't move as you breathe.
• Close the valve and watch for a drop that says something is leaking.
• Deploy it on the boat with one hand. If you need two hands to get it out from under the band, fix the stow.
• Read the gauge while the bottle is clipped to you.

Isn't it just a spare regulator?

The comfortable belief: a stage reg is a spare. Any old regulator will do.

The truth: it's the regulator you breathe when you're most committed. Deep on a stage, extending your bottom time. Or at a deco stop, when going straight up isn't an option.

That's not the place for a hand-me-down reg with a mystery hose.

Set it up once, then switch to it a hundred times

A good stage regulator becomes invisible. You reach for it and it's there. You read it and the number is clear. You stow it and it disappears again.

Gas switching, bottle handling and the failures that come with them are the core of the Stage and/or Deco Bottle Extension.

So, can you deploy yours with one hand? Without looking? Every time?