Second stage with mouthpiece, breathing-resistance control knob and venturi lever in pre-dive position.
The C370 second stage really looks the business. It’s modern, flash and quite distinctive, with a big chrome triangle almost surrounding a blue S, the Scubapro logo, on the front of the regulator body.
The result wouldn’t look out of place on the chest of a Marvel superhero, and the build quality suggests that when the final fight-scene is over, the C370 would still be standing.
And there is no shortage of features. On the left of the C370 you’ll find a venturi adjustment lever and a breathing-resistance control knob.
The venturi lever offers two positions, pre-dive and dive, and is effective in preventing free-flows on entry when the reg isn’t in your mouth. Try dunking your own reg in the water, mouthpiece uppermost, and see what I mean.
The breathing-resistance control knob is marked + <—> – and turns through three full revolutions to get from one extreme to the other, so there is plenty of adjustability for fine-tuning to your personal preference.
I, for example, prefer my regs set to deliver the maximum volume of gas they can, on the grounds that there’s no point in spending hard-earned brass on a reg that flows loads of gas, and then turning it down.
I’m prepared to live with the consequences of that decision, but the C370 turned out to be a very civilised performer, cracking open smoothly and delivering plenty of volume, but without the larynx-freezing blast that some regs can deliver.
And when I dialled the flow down as far as it went, at which point I felt as if I was taking part in an experiment to simulate an asthma attack, it still operated smoothly.
Some divers prefer a reg they need to work at to crack open, and the C370 should keep them as happy as I was. I even tried coupling the second stage to an ordinary, non-HFP/LP port, and was still happy with the performance.
I will mention, however, that with the venturi set to dive and breathing-resistance set as low as possible, it’s easy to catch the purge and make the C370 freeflow even in warm, dry air.
The purge, by the by, is the S on the front face of the second stage. It’s easy and progressive to operate, bare-handed or with gloves.
The exhaust T is quite narrow, but in good trim I didn’t find the bubbles of exhaled gas
any sort of distraction. I did, however, find the mouthpiece a bit soft, though it was easy to hold in place and I didn’t notice any jaw-ache on long dives or doing four dives per day.