26/05/2026
**S7 CCR Review — First Impressions from Open Water and Caves**
I am one of the lucky few who has had the chance to take a very detailed look at the S7 from Sump UK. I tested it in both open water and caves, and the benefits of its compact size were immediately obvious on day one — at just 5 kg and roughly the size of a 2 L tank, it's genuinely in a class of its own. Cave diving logistics in Portugal can be challenging, and larger units often make life difficult. This is exactly where the S7 truly shines.
It's not just the size — the build itself is remarkably simple. And that simplicity isn't only useful for explorers; it benefits everyone. The S7 has a single counterlung, an integrated axial scrubber, a head, a base, one Dual MAV that handles both diluent and O2 with a needle valve, and a DSV with loop. That's it. No more than a handful of O-rings in the entire unit.
A huge compliment has to go to Andrew Goring, the inventor of this CCR. The S7 is a true testament to his genius and engineering craftsmanship — every detail feels thought-through, refined, and purposeful. It takes real vision to build something this elegant and this simple at the same time.
The build quality deserves a mention of its own. It feels sturdy and pleasant to handle, and only high-grade materials are used throughout. I honestly wonder if it's even possible to break it.
The scrubber design impressed me in particular: it's an axial scrubber with 1.9 kg capacity and up to four hours of runtime, and the top cover is pressed down by a spring. If the scrubber settles during transport (for example while driving), the spring continues to push the cover down, so there's no gap for CO2 channeling. For tough speleo logistics, you can also run just 1 kg of absorbent for shorter dives to save weight.
The counterlung doubles as the water trap. With a 5 L counterlung and a dedicated 1 L water trap section at the lowest point, plus an OPV right where the water collects, clearing is very easy and flooding the unit is genuinely difficult.
You can attach two electronic devices — one AK4 port comes standard, with a second blind port ready for a HUD, NERD, or second monitor. It works with any AK4 cable. I used it with the Petrel 3, but an OSTC works just as well. Both galvanic and solid-state cells are supported (three cells with coaxial connectors).
Versatility is where the S7 really stands out. It can be used as a bailout CCR, main CCR, O2 CCR, staged, shared, dumped (in case of flooding), backmount, sidemount, no-mount… the options are basically endless.
Getting the unit ready is fast — very fast. Cleaning? Also fast. More time for coffee, planning, or preparation. Using it in the cave was fantastic. The needle valve is precise and a real pleasure to use; holding PO2 with it was no problem at all.
I was also lucky to dive with Anton Zhuchkov from the IDF (International Diving Federation), which added a lot of value to the experience. Anton is a true master across all classes — small ego, big knowledge, and always happy to share.
So that's my short review. The unit will be available on the market from September 2026.
If you're interested, feel free to get in touch with me. 😉
We teach it in Switzerland and Philippines
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