After training more than 1000 divers, one of the most common CCR questions we hear is simple: what happens to the gas after I exhale? A closed-circuit rebreather recycles that gas, removes CO2, adds back the oxygen your body used, and lets you breathe quietly and efficiently through the loop.
How a rebreather works
On open circuit, every breath you exhale is wasted as bubbles. A CCR keeps your gas in a loop: you exhale into a counterlung, the gas passes through a scrubber filled with CO2-absorbent, oxygen sensors measure the partial pressure of oxygen, and a controller (or you, manually) injects a small amount of oxygen to top the loop back up. You then inhale the cleaned, oxygen-corrected gas again.
- Counterlungs — flexible bags that let you breathe in and out of the loop.
- Scrubber — a canister of absorbent that chemically removes exhaled CO2.
- Oxygen cells — sensors that continuously measure the loop PO2.
- Controller & solenoid — keeps the PO2 at a chosen setpoint by adding oxygen.
- Diluent — air or trimix that fills the loop volume and dilutes the oxygen at depth.
Why divers move to CCR
- Optimal gas the whole dive — the unit holds an ideal PO2, so no-deco time and decompression efficiency improve dramatically.
- Massive gas savings — a few small cylinders can support hours underwater, regardless of depth.
- Silence — almost no bubbles means marine life stays close and photography improves.
- Warm, moist gas — recycled gas is warmer and more humid, so you stay comfortable on long dives.
Open circuit vs. closed circuit
Open circuit is simple and forgiving — ideal for learning to dive. Closed circuit is more complex and demands discipline, checklists and training, but rewards you with range, quiet and efficiency that open circuit simply cannot match on deep or long dives.
Train in Cyprus
Try CCR for yourself
A guided Try-CCR session is the best way to feel the loop. We will walk you through the unit and put you in the water in a controlled environment.
Instructor Insight
After training CCR students on several platforms, we have found that the unit is rarely the hardest part. The real work is building repeatable procedures: pre-breathe, PO2 checks, buoyancy, bailout and team communication.
— Yurii Prokhvatylo
Instructor Insight
One of the biggest mistakes new CCR divers make is focusing on equipment before procedures. Master the procedures first. The equipment becomes much easier afterwards.
— Yurii Prokhvatylo
From the Training
During CCR training on Cyprus reefs and around the Zenobia, students usually improve most after the second day, when loop awareness stops feeling like a separate task and becomes part of the dive.
Frequently Asked Questions
Who is What Is CCR Diving for?
This section is for divers who have heard about CCR but need a plain-English explanation first. It helps you decide whether the basics of closed circuit rebreathers fits your current certification, experience and goals. The aim is practical: understand the next step, prepare better questions and avoid choosing a dive or course only because the name sounds exciting.
What should I prepare before focusing on the basics of closed circuit rebreathers?
Before focusing on the basics of closed circuit rebreathers, be honest about recent dives, comfort in the water, buoyancy, gas awareness and equipment familiarity. Bring certification details and any limits you already know. That makes the conversation more useful than a generic recommendation and helps us suggest a realistic next step.
How does the basics of closed circuit rebreathers apply to diving in Cyprus?
The basics of closed circuit rebreathers matters in Cyprus because warm water, good visibility and access to serious dive sites let training move from controlled practice to meaningful dives. The environment is comfortable, but the standards do not change. We still plan the dive, brief the team and build skills progressively.
Can the basics of closed circuit rebreathers support CCR training, bailout planning and loop control?
Yes, when it matches your level. The basics of closed circuit rebreathers can connect naturally with CCR training, bailout planning and loop control, but it should not be rushed. We usually look at your recent experience first, then choose a route that keeps the training useful rather than simply adding a bigger objective.
What mistake does What Is CCR Diving help divers avoid?
The common mistake is treating the basics of closed circuit rebreathers as a label instead of a set of habits. Divers often want the destination, certificate or tool before the underlying skill is stable. Good preparation keeps the plan simple, exposes weak points early and makes the real dive calmer.
When should I ask GoToDive about the basics of closed circuit rebreathers?
Contact GoToDive when you want to decide whether CCR is worth exploring. Send your certification level, recent dive history, dates in Cyprus and the outcome you want. A short, honest message helps us tell you whether to train first, dive first or build a staged plan.
Original GoToDive Photos
Surface loop check
Teaching point: the visible loop makes this card about pre-dive discipline and unit control.
Bailout cylinder position
Teaching point: the card shows access, balance and bailout awareness in one image.
CCR instructor signal
Teaching point: CCR teaching is about small confirmations made before problems grow.
Rebreather trim drill
Teaching point: the image communicates trim and control without needing a long explanation.
Rebreather unit reference
Teaching point: this card supports checklist thinking, configuration and component awareness.
Continue Learning
CCR On Zenobia
How loop discipline changes when the wreck becomes big, deep and task-loaded.
CCR Checklist
A practical pre-dive flow for rebreather preparation.
Technical Diving
The open-circuit and mixed-gas skills that support advanced CCR diving.