"If you can float, neutral, two feet below the surface without moving a muscle, that's when you've really got your buoyancy dialled in."
An instructor at one of the first shops where I used to hang around making a menace of myself once told me that. Taking it as a dare, to this day, I frequently do exactly that: pause for a moment only a few inches under the surface.
This does absolutely zero for deco, mind you. It's just a party trick.
But it does lead me to think about something I noticed about the cavern tours swimming around us yesterday as we exited from a glorious 2.5 hour dive down into the Room of Tears basement area, hitting every single end of the line.
"You can fine tune your buoyancy using your lungs!" said every single open water instructor everywhere. I am certain you, yourself, have heard exactly that. May have taught it. I certainly did.
Correcting that absolutely wrong thinking is probably the thing that now I struggle the most with as an instructor.
Poor trim is a tell-tail sign, but it's the bubbles that really give it away. As someone is swimming along, increasingly head down, eventually the attitude grows too steep or they finally notice that if they stop kicking they start to float up. Just as often as not, during cavern tours, this is right about the moment they find themselves stuck to the ceiling.
The entire contents of the BC get dumped as they try to extricate themselves. With that, a new problem is created as they start to sink; or, in some cases, start falling through the water column like Wile E. Coyote.
Sometimes the result is an enormous silt cloud as the diver goes vertical to start kicking upwards to arrest the fall. Sometimes it is a Wile E. Coyote-like, diver-shaped mushroom cloud erupting around them as they hit the floor.
Eventually, some simulacrum of buoyancy is reached and the diver proceeds, now in a significantly foot-down trim. Presumably confident that they have gotten back to being neutral as the good diver they are.
Know what happens to a diver in foot-down attitude when they stop swimming? Or when they don't consistently breathe at the top fo their lungs - never fully exhaling, which has all sorts of gas exchange implications as well?
Yep. They sink.
Not neutral, then.
But this cycle of adding too damned much to the bc, then dumping way too much to overcompensate, and so on, back and forth, like trying to pull focus on a very silty picture.
Something I've noticed people say, as I've worked with them to help try to break these habits: "I feel like I was constantly adjusting my buoyancy."
And I smile an inward, empathetic smile. Because it means they're almost starting to get the picture, but they're not there yet.
You know how often I adjust my buoyancy? How often I've got the power inflator in my hand, or am dumping something out of my wing?
Not a lot. Not frequently. Constantly. There is rarely more than a minute or two that goes by that I'm not making tiny adjustments.
And that is the real trick. Tiny adjustments, as opposed to the dramatic showpiece adjustments made by the stars of our cavern tour. The tiniest spritz of air into the wing descending two feet into a hole... only a bubble or two burped out during a three-foot ascent over some breakdown or a coral head. Literally any ascent or descent at all calls for attendance to the volume of the wing.
Do not control buoyancy with breath. Breath is for keeping you alive; breath normally. The Buoyancy Control Device is for controlling your buoyancy.
Keep those two things separate. Would you breath the contents of your wing? Oh, don't even start with this, "in a pinch" crap. Monitor your gas supply. Oh... and drysuits are thermal protection, not buoyancy control.
Breaking that muscle memory is hard. Really hard. No matter how badass your famous instructor might act... they had to break that muscle memory at one point or another themselves. Because "use your lungs to fine tune your buoyancy" is simply how diving is taught. Everywhere.
And why people sometimes struggle for the first few days of a class, unable to hold position, never feeling quite in control of things, easily distracted or task-focused, always dealing with this little background struggle during damn near every minute of every dive.
Because they're really, really used to, say, breathing from the top of their lungs. And the moment they do, say, a valve drill they are in the middle of a task... and suddenly caroming around the bottom.
When people feel like they've been constantly adjusting their buoyancy I take some delight in pointing out that they'd touched their power inflator only ten times during an entire dive. That's not "constantly."
Swimming around with the thing damn near in your hand at all times is constantly. And not entirely unwarranted.
You might try (if this ain't already your thing) a dive where you spend the entire time making teensy, tiny, infinitesimal adjustments. Stop periodically, but very very suddenly to assess your buoyancy. Can you hold perfectly still or do you need to scull your fins? If it's the later, see about more tiny incremental adjustments until you don't have to.
No mistake, this process is tedious. Which is probably why it's easier to tell open water students, "Just breath real deep to stay off the coral." But the slow, tedious process of finding truly, absolutely neutral is 100% worth it.
You use less gas, both because you're exerting less effort in the battle for neutrality, because you can breath more normally and comfortably, and less gas gets wasted in the add-too-much-dump-too-much cycle.
And just as much, if not more importantly, tasks all get really easy really quickly when you can hold perfectly still. You can maintain position relating to your task - whether it's a photo, or some linework, or needing to assist a buddy with something - far more effortlessly, freeing up your attention more fully to the task at hand.
And, finally, it's just more comfortable.
You know that fancy-pants, rockstar instructor who just floats, perfectly horizontal, perfectly neutral, not moving a muscle, seeming like a still photo in the water? Yeah, it really is as comfortable as it looks.
Granted, it's hard work to where you can do it without thinking about it. But, I mean, it's not a magic trick.
- Breath normally - Make very small buoyancy adjustments - Make those adjustments way more frequently than you're used to so you can stay in front of your buoyancy - Depth changed by more than a foot? Fix your buoyancy. - Assess your buoyancy constantly throughout the dive; not every few minutes... constantly.
Totally worth it.