The Demon at 10 meters

 "There was a demon that lived in the air. They said whoever challenged him would die. Their controls would freeze up, their planes would buffet wildly, and they would disintegrate. The demon lived at Mach 1 on the meter, seven hundred and fifty miles an hour, where the air could no longer move out of the way. He lived behind a barrier through which they said no man could ever pass. They called it the sound barrier."

-The Right Stuff (1984)

 

Along with the Monsoon, the departure of Johnny, and the arrival of Sebas, a demon appeared.

I feel I must clarify: I mean demon in the Eastern sense. Less the minions of Satan, Western demons represent disorder.

 I was instructing a pair of Brits and a Russian guy, Alexandrev. The Brits were doing well, but the Russian was diving down with his arms crossed. A cross between stubborn and a non-native English speaker, he wasn’t responding to my miming/coaching.

The next day, Alexandrev was again with me. I followed 10 feet behind him as he dove, checking his posture. It had improved from the previous day, but it wasn’t perfect. Good enough for the day. He turned at 87 feet and kicked toward the surface. I met him face to face at 66 feet and watched his eyes as we kicked to the surface. He looked relaxed and normal. The pressure change from 66 feet to 33 feet is only 17%. At 33 feet (10 meters), you are feeling twice the normal pressure that you usually feel on land. Going from 33 feet to zero is the most dangerous part of a dive:  50% pressure change and Dalton's Law. Your lungs can actually leach oxygen from your blood. This is the cause of Shallow Water Blackout - almost all Freediving fatalities-  and I was about to witness it.

Above 33 feet, Alexandrev still looked good. He was looking up, periodically, at the buoy.  I did too because I didn’t want to headbutt someone on the buoy who wasn’t paying attention. Alexandrev moved slightly away from the line so he wouldn’t headbutt the buoy itself. I don’t remember if he broke the surface first, but I could tell that the rough sea had pulled the buoy inches from his grasp. I reached over the buoy to grab his hands. It is standard for an instructor to treat a diver like a blackout victim after every dive. We scold our student if they don’t come up and bear hug the buoy while doing the mandatory four recovery breaths.

Instead of grasping the buoy as instructed, he went limp. His breath came out in a fizzle. A passing wave splashed his face. Water drooled out of his slack mouth. I was pulling him towards me, holding one hand and awkwardly grabbing his shoulder. He was shuddering against me, making half-cough sounds that told me he was not fully blacked-out. “Breath, buddy!” I shouted.

Bat, having witness something similar with Angus the day before, was right there. Bat removed Alexandrev’s mask, letting him breathe through his nose. Special nerves around your nose and eyes automatically tell your brain if you are submerged or not; removing the mask tells the brain that it is okay to breathe.

I held the Hunter-buoy-Alexandrev sandwich for a few moments more as he took ragged breaths. He suddenly looked and me and tried to push me away. He was out of the ‘grey area’ and didn’t have a recollection of the last 6 seconds. “Breathe, man.” 

I escorted him to the boat. Once you have a blackout or any loss of muscle control (Samba), you are done for the day. He was back diving the next day and had no problems. He knew his limits and knew to relax. A lot of people would think he suffered brain damage, but all the research shows that a minor Samba or blackout does about as much damage as a glass of cheap red wine. 

The body is good at self-conservation. The pressure and low oxygen levels cause the body to shift blood from the extremities to the vital organs. The heart, lungs, and brain get most of the blood/oxygen. When oxygen levels drop even further, the brain starts shutting down "unnecessary" functions, like fine motor control. Even lower? Loss of consciousness. Even after a total blackout, the brain continues to function in "sleep mode" like a computer. Revival after a blackout takes mere moments; the body and brain come back "on line".

I have only had one Samba. It was almost a month ago and a weird dive. I wasn't quite focused. I thought I went a lot deeper than I did. I came up, feeling tired and when I grabbed the buoy, I felt faint. I did my recovery breathing, but I couldnt stop my lower lip from quivering. Shifu saw this, asked me questions and I was slow to respond. He took me back to the boat. The next day, I was felled with Dengue Fever.

For three straight days this week, someone had a similar, minor incident. Mike the Israeli had a Samba after a dive to 60 feet. A new student had a Samba after an even shallower dive. My mask mysteriously imploded and sank (alas, but it served me well for three years). The demon was disturbing our idyllic isle.

Shifu was worried. We always follow the published procedures in the manual to the letter. We don't push our students and set conservative, realistic goals for everyone. Yet, the Sambas kept happening. The human body has so many variables that can make one prone to Samba, even after a conservative dive. The body can "over-compensate" for the pressure change. We joked that Sebas brought a Samba demon in his luggage.

Then, one day, the Monsoon slacked off. Sambas stopped happening. Our demon gave us respite but we know he is still there. He is physics, lurking in that 50% pressure change between 33 feet and the surface.