Technical diving

Closed Circuit Rebreathers

Recycled breathing gas, silent diving — and support that is specific to your exact unit.

Closed-circuit rebreathers recycle breathing gas and continuously manage the breathing loop's composition, scrubbing carbon dioxide and adding oxygen as it is consumed.

The benefits are long gas duration largely independent of depth, minimal bubbles, warm moist breathing gas and an optimised oxygen partial pressure throughout the dive.

The risks are different in kind from open-circuit diving, and so is the support infrastructure a rebreather diver depends on.

The failure modes

Open-circuit failures are usually obvious. Rebreather failures are frequently silent, and a diver can feel fine while the loop becomes unbreathable.

hypoxia from insufficient oxygen addition
hyperoxia from excessive oxygen
carbon dioxide problems from scrubber exhaustion or channelling
oxygen sensor failure or drift
loop flooding
scrubber failure
electronics failure

Support is unit specific

CCR support is not one capability. A centre may service one manufacturer's units, stock a particular sorb and have instructors qualified on specific models.

A centre page should name supported units where possible, because a rebreather diver arriving with an unsupported unit effectively has no support at all.

which units are supported for training
which units can be serviced
sorb availability and brand
oxygen and diluent fills
bailout cylinder hire
sensor replacement stock

Cave diving, represented by an AI-generated editorial image.

Related training

Closed Circuit Rebreather DiverRecycling breathing gas to extend duration, reduce bubbles and optimise oxygen exposure.Advanced NitroxHigh-oxygen decompression gases and oxygen-clean equipment — not ordinary recreational Nitrox.Decompression ProceduresPlanning and executing dives with a mandatory decompression obligation.Trimix DiverAdding helium to manage narcosis, oxygen exposure and gas density at depth.

Where this applies in Australia

Ships' GraveyardNumerous vessels deliberately scuttled outside Port Phillip Bay across a wide depth range.Port Phillip Heads WallsWalls starting at 12 metres and continuing beyond 90 — the terrain behind Victoria's technical culture.Tank CaveOne of the longest underwater cave systems in Australia — advanced CDAA qualification only.

Centres where this capability is documented

Documented does not mean verified in every detail — confirm the specific service directly.

Abyss Scuba DivingA Sydney operation associated with training across recreational and technical levels, boat diving and equipment services.Perth ScubaOne of the most fully documented operations in Western Australia, covering recreational, professional, technical and freediving training alongside substantial equipment facilities.Dolphin Scuba DivingA Perth business providing training, equipment and service support.Tasmania Tech and Dive CentreThe Tasmanian operation most clearly associated with technical diving services, spanning recreational and technical training with technical gas support.

Frequently asked questions

Is CCR support available across Australia?

It is concentrated in the major cities and specific technical centres, and it is unit-dependent. Confirm both sorb availability and unit support before any trip.

Should I choose a unit based on my local centre?

It is a strong consideration. Ongoing servicing, sorb supply and instructor availability matter more over time than the initial purchase decision.