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Commercial Diving – The Pit

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Prepping for The Pit
Prepping for The Pit

After getting zipped into my drysuit, I shrug the harness and bailout bottle onto my shoulders, then buckle the straps tight around my chest. Zach, the standby diver, carefully lowers the yellow, 33-pound Kirby Morgan Superlite helmet over my head, the pads inside the shell hold it in place, while the teardrop shaped mask covers my nose and mouth. He mates the bottom of the hat to the aluminum ring on the neoprene cone snug around my neck, then latches it shut. My ears pop with the changing pressure and the sound of my breathing echoes in the fiberglass shell. I adjust the free flow, then give Zach a thumbs up.

By Mark Norder

After a com check, he helps me up and I step onto the stage. Turning around, I face my tender while he clears my hose. One last com check and the metal stage, shaped a bit too much like a vertical coffin, lowers me into the caisson.

Eight feet below the caisson cover, the stage enters the mud thick water, stopping just beneath the surface. I reach over and grab the four-inch diameter, canvas-covered hose that will guide my descent to the jet nozzle on the bottom. Stepping off the stage, I have a brief view of the cement wall before everything goes dark, the way only the blind and commercial divers know dark.

Going hand over hand down the jet hose, I soon reach the mud floor and realize my helmet’s leaking. Water rises above my chin and every exhalation splashes up my nose. A spark of terror reminds me that it is panic, not the black water, that will kill me. Calming myself down, I work to fix the problem, if I can’t, at this depth, no help can reach me in time. By keeping my chin down, I’m able to pinch off the leak in the neck dam, stopping more dirty water from filling the helmet.

Prepping for The Pit
Prepping for The Pit

“OK, Ben, I’m good to go.” I say.

“Roger that.” Ben replies. “Let’s take a pneumo first.” 

As air pressure overcomes water depth, I feel bubbles percolate out the open-ended hose tucked into my harness.

“Got bubbles.” I tell Ben. Up in the dive trailer, a pressure gauge, connected to that hose and calibrated in feet rather than PSI, shows Ben my depth.

“A hundred eighteen feet,” he says. “Time to get to work, old man.”

“Roger that.” I reply.

Wanting to understand what my divers are facing, I let my hands tell me about the site. The hard mud bottom is flat and barren, the cement walls, slick and cold. I find the airlift a few feet out from the side, the intake just inches off the mud, ready to collect what my jet nozzle will soon push its way. I’m careful not to foul my umbilical on this 12-inch diameter hard rubber pipe, or the high-pressure air hose that will push mud up the pipe.

Feeling my way along, I end up back at the jet nozzle. Setting the four-foot-long, inch and a half diameter pipe on my shoulder, like an old bazooka in a war movie, I aim it down towards the airlift. “On, on!” I say to Ben, and the hose stiffens as the high-pressure water jet tries to push me backwards. I begin sweeping the nozzle left to right: the way you’d use a garden hose to wash leaves off the driveway.

Before long I hear “We got mud!” from Ben, telling me I’m aiming in the right direction and my efforts have changed the outflow from dirty water to thick, rocky sludge. After a while, I pause for a minute so the topside crew can lower the airlift back into the dropping mud level. Thirty-eight boring minutes after I reached the bottom, Ben tells me it’s time to secure and prepare to surface. The jet pressure drops, and I lay the nozzle down on the mud floor. We take one last pneumo before I start climbing the jet hose, speeding up or slowing down as instructed for a safe accent.

After making my required safety stops at 40 and 30 feet, I’m ready to leave the water, but my hose is fouled. It takes a few minutes and some guidance from my tender to work myself around the airlift pipe and back onto the stage.

Out of the water, the tender and Zach remove the helmet and harness, yank off my drysuit and undergarments, and strip me near naked, all while I’m stumbling out of the pump house and over to the chamber. As the hatch is dogged behind me, the sound of air pressure filling the small compartment tells me my decompression has begun.

I’m popping my ears on the descent, when Adam, the chamber operator knocks on the small, round view port. He gives me a thumb and forefinger “OK?” and I give him one back, holding it up against the port during the entire pressurization. Soon, my outer lock reaches 50 feet, matching the pressure of the inner lock and I’m able to push open the hatch and crawl inside. Dogging it behind me, I put the oxygen mask on, stretch my long, lean frame out on the mat and begin my decompression schedule. Lying there with the O2 bib strapped over my nose and mouth, I’m feeling pretty damn good; relaxed and optimistic. Wondering why, I remember all that nice, pure oxygen that’s flushing excess nitrogen from my system, clearing my head, and taking me back to the beginning of this dark journey.