Helium in the loop, depth to 60m, and the deep Malta wrecks finally accessible on rebreather. If CCR Air Diluent showed you what rebreather diving feels like, this is where you find out what it can actually do.
You're a qualified CCR diver. You understand your unit, you've got your pre-dive checks automatic, you know how to respond when the handset tells you something you don't want to hear. Now let's go deeper. Helitrox — a helium-oxygen diluent mix — extends CCR diving to 60 metres with managed narcosis and the kind of bottom time that open-circuit trimix divers look at with open envy.
Adding helium to the loop changes things. The gas density decreases, which is a genuine advantage at depth. The narcosis fraction drops, which is the point. But it also introduces isobaric counterdiffusion considerations that are more complex in a CCR context than in open circuit, and the setpoint management across a deep dive with a helium diluent requires careful thought and disciplined execution. This is not a course where you just swap out the diluent cylinder and dive the same way.
HMS Stubborn sits at 56 metres. On CCR with helitrox diluent, you can spend genuine time on her — not the compressed bottom time that open-circuit divers are managing, but proper exploration time with a fraction of the decompression obligation. Le Polynesien at 65m becomes accessible for divers pushing to the depth limit of this qualification. These are transformative dives, and they're exactly what this course is building toward.
Over 5–7 days we'll go through the theory — helium in the loop, diluent selection, setpoint strategy at depth — before getting in the water and applying it progressively. We'll start at moderate depth, confirm your unit handling is solid with the new diluent, and build up to the target depth on genuinely interesting sites. I don't rush this progression. Getting to 60m on a rebreather isn't an achievement if the execution is sloppy.
Malta is a brilliant place to run this course because the water is warm enough to spend real bottom time, the visibility lets you actually see the wrecks you're on, and the sites at this depth range are genuinely exceptional. I'm not going to pretend the deep stuff is as convenient to access as the 30m sites — it requires a boat, proper logistics and careful planning — but that's all part of what makes it worth doing.
Your bailout gas requirements increase significantly at 60m compared to 30m air diluent diving. We discuss this in detail during planning — bailout cylinder configuration for deep CCR dives is an important logistics conversation to have before the course.
CCR Mixed Gas / Helitrox opens up the 40–60m depth range on rebreather — which in Malta means HMS Stubborn, Le Polynesien approaching the limit, and a completely different experience on the wrecks you've already dived shallower. The next step is CCR Decompression Procedures, which focuses specifically on managing extended deco obligations on the unit.