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.
A rebreather choice is a system choice
The unit
Identify the exact rebreather and its manufacturer documentation.
The instructor
Confirm instruction for that unit and intended training level.
The support
Discuss servicing, consumables and local ongoing support.
The scope
Match the training to the diving being considered.
Original YouDive visual discussion guide. Use the article and its sources for context; qualified review is pending.
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
Common 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.
