I recently sat down with Tamara Adame on her podcast, Tech Diving On Air, to talk about the psychology of extreme environments, including what happens in the nervous system during a military deployment or a cave dive, and why the two have more in common than people expect. One question kept coming back, in different forms, for the full hour: why would anyone feel more at peace a thousand feet into an overhead environment, breathing compressed, than they do at their kitchen table?
It sounds like a contradiction. It isn't. But explaining why requires a distinction that's central to a lot of clinical work, even though most people have never been given language for it: the difference between hypervigilance and absorption.
Two Ways of Paying Attention
Hypervigilance is the running background awareness of whether you're safe, whether you're performing acceptably, or whether the ground under you could give way. It's an old survival system, and it's appropriate when there's real threat. The problem is that it's expensive to run, and a lot of people run it constantly, not necessarily because they're in danger every hour of every day, but because something in their history taught your psychology or nervous system not to trust the "all-clear."
Absorption (or flow, engrossment, etc.) is the opposite state: full, legitimate engagement in something, with no spare attention left over for self-monitoring. Digestion, immune function, sleep architecture, and the parasympathetic side of the nervous system I talked about with Tamara, all depend on the body believing, at a non-verbal level, that it doesn't need to keep watch. People who rarely get access to absorption don't wear down gradually. They wear down the way sleep deprivation wears people down, because functionally that's close to what chronic hypervigilance is: a system that never gets to stand down.
This shows up constantly in the therapy room: combat veterans who can't relax in a crowded restaurant; survivors of unstable or unpredictable households who scan every new relationship for the moment it turns; people with social anxiety who can't enjoy a party because part of them is always narrating how they're coming across. Different histories, same underlying mechanism: the monitoring never turns off long enough for anything else to happen.
The Monitoring Has to Become Automatic Before It Can Disappear
Here's where cave diving turns out to be an unusually clean illustration of the mechanism. A new diver in an overhead environment cannot relax. Every few seconds there's a gas check, a line check, a buddy check, a depth check, a mental note of the exit. This is appropriate but it's also hypervigilance functioning exactly as it should in a genuinely unforgiving environment. If a diver stayed in that state indefinitely, the cave would wear them down the same way any sustained threat-monitoring does: narrowed attention, degraded performance, and eventually the irritability and pessimism that show up in anyone deprived of rest for too long.
What changes with training and hours isn't that the monitoring stops, it's that it stops requiring conscious effort. Gas planning, trim, buoyancy, line following, for example, become procedural rather than deliberate, the way an experienced driver doesn't consciously think about the clutch (if you're old enough to remember such antiques). That's the same shift therapy is meant to address, just in a different setting, which is moving a threat-response from something effortful and foreground to something trained and automatic, so the person underneath it is free again. Once the monitoring is automatic, the diver is left with something most of us rarely get on the surface — total absorption, with the vigilance still running underneath, unattended, doing its job without asking to be thought about.
That's a flow state in the technical sense: full engagement, collapsed sense of time, no spare attention for self-evaluation. The cave doesn't let you fake it, either. You cannot be worrying about your inbox or a strained relationship while you're a few thousand feet or two hours back in a passage with a single point of failure. The environment enforces the very thing therapy tries to create on purpose.
A Potential Complication
I don't want to oversimplify this, because the same mechanism that produces restorative absorption also produces a dangerous look-alike, and confusing the two is how people get hurt both underwater and otherwise. We talked on the podcast about normalization of deviance, the process by which experienced divers stop perceiving risks that would terrify a newer diver, not because they've mastered the risk but because repeated exposure without consequence quietly recalibrates what feels dangerous. From the inside, normalization of deviance and genuine trained absorption can feel identical: calm, fluent, unbothered. The difference isn't the subjective experience. It's whether the calm underneath is built on real competence and honest risk assessment, or whether it's just habituation dressed up as mastery.
The same distinction matters in mental health. Someone who's stopped feeling anxious in a genuinely unsafe relationship or situation isn't necessarily healed; rather, sometimes they've just been recalibrated by repetition, the same way a diver can be recalibrated by getting away with cutting corners. Good therapy, like good dive training, is largely in the business of keeping those two states — earned safety and mere habituation — from becoming indistinguishable to the person living inside them.
The Clinical Takeaway
The good news, depending on your proclivities, is that you don't need a water-filled cave to engage this process. Absorption requires two things: an activity engaging enough to occupy full attention, and enough trained competence that the necessary monitoring can run in the background instead of the foreground. Chess, surgery, a musical instrument, a well-run kitchen line, and even therapy itself when it's working, all ask for the same architecture. The question worth sitting with isn't "what's my hobby?" It's closer to: "where in my life has the vigilance become automatic enough that I can actually let go into what I'm doing?" and "where am I still, without realizing it, standing watch?" If you don't have an answer, that's usually not a character problem. It's usually a training and safety problem, and both of those are workable.
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*You can hear the full conversation with Tamara Adame — including the physiology of fear and what "mental hydration" means in practice — on the podcast Tech Diving On Air. If any of this resonates and you'd like to explore how to how to reduce hypervigilance or cultivate absorption, reach out through the website or call the office at 720-675-7918.
