The next day our class meets about a hundred miles inland from Tampa in a dirt parking lot outside the town of Ocala. Across the lot, in the shade of candleberry trees, is a dent in the ground that looks like it's been punched by a giant, angry fist. At the bottom of the hole is a pool of bright green water known as the 40 Fathom Grotto. As the name suggests, it plummets down more than 240 feet.
For the past forty years, emergency rescue workers have used the grotto for advanced scuba training. Before that, the locals used it as a public dump. It's still filled with all manner of junk: rusty motorcycles, satellite dishes, a 1965 Corvette, a few Chevys, an Oldsmobile, innumerable bottles and cans. On one ledge, about forty feet down, is Gnome City, a collection of plaster gnomes and gnome castles placed there by divers; it's set against a limestone wall covered in the fossilized remnants of fifty-million-year-old sand dollars. Even this water hole, fifty miles from the coast, was once part of the ocean.
At ten o'clock, Pinon swims two floats out to the middle of the grotto and connects them with a yellow rope. Our class pulls on wetsuits, masks, snorkels, and fins, and we slip in. In the hazy morning light, the water is a dull sapphire green with poor visibility, maybe twenty feet. The depths below that look black and brooding. We swim out to the floats and clutch the rope, dangling in single file like socks on a clothesline. We'll be here for the next four hours attempting to freedive to sixty-six feet.
"Our first dive will be down to five meters," Pinon says. "This is an easy dive, just to get warmed up." Because the grotto is filled with fresh water, which is less dense than salt water, we'll be about 2.5 percent less buoyant than we would be at sea. This doesn't sound like a lot, but for freedivers, it's a significant difference. We'll sink faster and will have to exert a bit more energy during our ascents.
The human body in its natural form—with little or no clothing—has the ideal density for freediving; no weights are necessary to aid its descent. However, the thick wetsuits we're all wearing throw off this balance, requiring each of us to wear about twelve pounds of weights in fresh water to compensate for the extra float.
The key to a successful deep dive is making oneself as hydrodynamic as possible. Loose clothing, extended limbs, or oversize masks can create drag, which will slow the descent and decrease depth and "down time"—freediver lingo for being underwater. When seals dive deep, they collapse their lungs, extend their spines, and often exhale air to reduce drag and gain depth faster and more easily. Freedivers do the same. "You put your arms to the side, head down, make yourself like a missile," says Pinon.
Sinking is relatively easy, especially after the first ten or so feet; ascending is less so, which is why freediving can be so dangerous. As with mountaineering, you need to know your exact halfway point and have at least 60 percent of your energy and oxygen reserves left to make the return trip.
During the ascents, we'll need to exhale all the air we've been holding at about seven feet below the surface. This allows us to immediately inhale much-needed fresh air at the surface without taking time to exhale, and it also helps protect against shallow-water blackouts. A few seconds could mean the difference between a successful dive and a samba or blackout. In freediving, success (in this case, remaining conscious) is measured not in feet or minutes but in inches and seconds.
As Pinon discusses the diving strategy, I notice a small group of scuba divers on a wooden float set up on the other side of the grotto. They are festooned head to toe with masks tubes, tanks, vests, belts, and other equipment. They can barely walk on land and can only lumber gracelessly through the water. Their movements are extravagant because they can afford to be. From where I'm floating, it looks awkward and wasteful. But then again, those divers never have to worry about imploding their lungs or blacking out.
Ben dives first. We watch through our masks as he breathes up, submerges, and pulls himself down along the rope until he reaches a weighted plate around fifteen feet. He taps the plate, pulls himself back up, resurfaces, and goes to the end of the line. Lauren, Josh, and Mohammad, one after the other, go next. They all make the dive without much effort. I follow but resurface after hitting just ten feet or so, my head throbbing.
"That's natural," Pinon says. "It takes a little time. Try it again next dive."
I ask Ben how he was able to descend and ascend so quickly. He mentions that he, Josh, and Lauren have been spearfishing for years. He assures me I'll figure it out.
The problem for me, and for most beginners, is equalizing. The optimal rate of descent for a freediver is three feet per second, which requires equalization in sinus cavities (making the ears pop) about once a second, otherwise you'll risk serious injury to the ear. Each pop must be complete; if it isn't, Pinon instructed us to immediately stop, back up, and try it again.
Pinon lowers the plate to thirty feet, then forty-five. Others easily make these depths, but I can't make it past fifteen feet.
At around two o'clock, it's time for our last dive attempt. The plate is now sixty-six feet down—the lowest depth allowed for beginners. It's invisible from the surface. All we can see going down is a yellow rope disappearing into hazy, dark green water.
It's a frightening prospect to dive down into water not knowing where you'll be when the rope ends or when you'll take your next breath. Everything I know about surviving in the ocean tells me this is a bad idea. But I start breathing up anyway and prepare to go deep.
Ben leads the group. He inhales one last time, then disappears. Forty-five seconds pass and we see no sign of him. Then, through the haze, he reemerges, pulling himself up the rope. He slowly resurfaces, breathes up, then goes to the back of the line. He made it down to sixty-six feet, seemingly without much effort. Lauren and Josh follow, all making the dive. Mohammad, a first-time freediver, makes it to about fifty feet, a commendable depth.
By the time it's my turn, the pressure is on. I try not to look down at the disappearing rope as I inhale my last breaths. Big breath in, bigger breath out. Repeat.
Pinon pulls himself around the float so that he's right beside me. "You need to make this dive. Say, 'James is going to make this dive,'" he tells me. I nod, inhale, duck my head under the water, and climb down the rope.
With every pull of my right arm, I retract my right hand, pinch my nose, blow air into my ears, and try to equalize. It starts to work. I keep pulling, hand over hand, like Jack and the Beanstalk in reverse, until I feel the pressure of deeper water tightening around me like a closing fist. To make my body more hydrodynamic, I've placed my head down, so that I'm looking horizontally across the water, like I would if I were walking. Pinon, who is following me on the other side of the rope, stares through his mask. He is watching carefully to make sure I don't exhale, start twitching, or black out.
I stare back and we hold each other's gaze as we both sink. The water around us grows darker, then darker still. A strange sensation grabs at my shoulders. It feels like a large hand is pulling at me. I loosen my grip on the rope and notice that I'm no longer drifting downwards. Every direction is washed in the same pale green fog, as if I'm trapped in an enormous marble. I wouldn't know which way was up or down if I weren't holding the rope.
Across the rope, Pinon is looking at me and shrugging. He puts his right hand in front of my mask and points down. He wants me to go deeper, I think. I shake my head no but he keeps pointing down. I notice that neither of us is holding the rope.
We're just suspended here, two middle-aged men floating upside down, staring at each other, shaking our heads in the shadowy depths of a freshwater former dump in central Florida.
Then it occurs to me that maybe down is really up, and that maybe Pinon is signaling for me to get back to the surface. Maybe something is wrong. Is this what it feels like in the pink cloud?
I snap out of it, but now I really want to breathe. A cough right now could sap my body of the oxygen I need to make it back to the surface conscious. This thought fills me with fear. I feel an unyielding urge to return to the surface, to inhale fresh air. I quickly turn my body around on the rope like a baton and begin pulling back up. Pinon follows close behind. With each pull, the water grows slightly brighter and brighter until I can see, about fifteen feet above me, rows of dangling fins between two floats. They look like upside-down birds on a telephone wire. I exhale all my air at what feels like seven feet, then resurface.
I learn later that I made it about halfway down the rope, to about thirty feet. Not awful, but not great either. This wasn't the doorway to the deep, but I was edging closer, starting to wipe my feet on the welcome mat. The tug of neutral buoyancy I felt just before I started back up the rope meant I was about ten feet away. For better or worse, the residual fear of being down there remained with me.
And days later, as I'm in the airport on my way home, I'm still shaking with excitement and looking around before I cough.
Excerpted from DEEP: Freediving, Renegade Science, and What the Ocean Tells Us About Ourselves (Eamon Dolan Books/Houghton Mifflin Harcourt), released June 24, 2014.