10/14/2026
Low Breathing Effort and Freeflow
Recently, another regulator brand made the following claim:
"Having a super-easy cracking pressure (low breathing effort) isn’t always what divers want: In high current, or working environments, it can be too easy to freeflow."
Well, not exactly.
First, cracking pressure and overall work of breathing aren't the same thing. And the relationship between cracking pressure, water flow, and freeflow is considerably more complex than that statement suggests.
Let's talk about something that doesn't get nearly enough attention: the design of the second-stage front cover.
Your regulator's diaphragm moves with every breath. The front cover must allow water to move freely as the diaphragm responds to changes in pressure. But how that water enters, exits, and flows around the cover matters enormously.
A well-engineered front cover manages that flow so that swimming into a current, or travelling along on a DPV, doesn't create unwanted pressure differences across the diaphragm that can initiate a freeflow.
You shouldn't have to sacrifice excellent breathing performance simply because you're diving in current or high flow.
And frankly, if you're looking for the Deep6 team underwater, there's a pretty good chance you'll find us in precisely those environments.
Now, there's an important distinction when it comes to your backup regulator or octopus.
Unlike your primary, it isn't sitting in your mouth. The open mouthpiece is exposed to moving water, and that can create conditions that encourage freeflow. That's one reason to use the pre-dive setting, where provided, and increase cracking pressure on regulators with an adjustment k**b when appropriate.
Those adjustments have a purpose. They shouldn't be confused with compensating for poor hydrodynamic design of the front cover on a primary regulator.
And what exactly constitutes a "working environment"?
Commercial diving? Technical diving? Cave diving? Working against current? Operating a DPV?
Those environments can certainly be demanding, but there's no inherent reason that simply working underwater should cause a properly functioning regulator to freeflow.
Of course, no regulator is immune to every possible combination of current, orientation, and pressure. But designing to minimize those problems while preserving excellent breathing performance is precisely what good engineering is supposed to accomplish.
Every regulator design involves compromises. The question is whether you engineer those compromises around the conditions divers actually encounter, or ask your marketing department to explain away the consequences. At Deep6, we choose the engineering.
In fact, when designing the Deep6 Signature second stage, we made deliberate choices about front-cover hydrodynamics. We knew we could squeeze slightly better breathing-machine numbers out of another configuration. In fact, we'd worked with a design that did precisely that. But we've also spent enough time riding DPVs into strong cave flow, doing real Public Safety operations in high current rivers, and on wrecks at silly depths on very high helium mixes in "rip your mask off" type current to know that the lowest possible laboratory breathing-effort number isn't the only measure of a great regulator.
So we made a conscious engineering decision: preserve exceptionally good breathing performance while improving resistance to current-induced freeflow and not chase the absolute best breathing loop technically possible on a machine because because we dive in challenging conditions, not an ANSTI breathing machine's chamber.
Because the best regulator isn't necessarily the one that produces the prettiest number on a machine. It's the one that performs best across the conditions in which you actually use it.
Our team dives in some of the most demanding environments we can find. We don't want to spend our dives thinking about spinning our marketing to compensate for poor design choices.
We want equipment that breathes exceptionally well, performs predictably, and lets us concentrate on the dive.
That's what expedition-grade equipment should do.
We'd rather solve a problem at the engineering bench than explain it away in a marketing post.
