Tulum, Mexico -- Gina, the short Texan dive master, grabs my left arm and prepares to hurl me into the dark pool of water.
"On three, Brian. Ya ready?"
Brian, her assistant, stands on my right side. He's ready. I'm not. I was ready this morning when I showed up at the dive shop - although "dive shop" is a glamorous moniker for the worn-out store somewhere south of Tulum.
Sitting in the finest lawn chair the establishment had to offer, I pondered the wisdom of leaving my shack by the sea to learn diving in a broken-down Mexican strip mall. I embraced the irony fully and handed over the money for something called a resort course.
The phrase "resort course" may in fact be a diving instructor's euphemism for "stupid tourist diving instruction". My surroundings are as much like a resort as Peter Boyle is like Drew Barrymore.
After a solid 45 minutes of instruction, Gina feels confident that I'm ready to face the uncharted depths for the first time.
However, while standing on the bank of the cenote, I begin to have serious doubts. And what is a "cenote," you might ask? It's the point where an underground river travelling through volcanic rock cracks the surface of the earth. From land, it looks like a scrubby pond surrounded by innocuous plants, but underneath this mild-mannered exterior is an incredible underwater world where the fresh water of the river mixes with the brine of the gulf.
"Oh God, he's heavy. One, two three..."
I find myself at the apex of a surprisingly high arc heading toward the water, and watch as my flippered feet bludgeon their way into the depths. Wonder of wonders, I can hear the sound of my own Darth Vader-like breathing. "Luke, I am your father and I can breathe underwater!"
Gina and Brian jump in after me and are making adjustments to their equipment. Gina fires off a few pre-arranged hand signals that might mean "All right, let's go!" or even "A shark is going to rip off your arm!" I agree with her wholeheartedly and we are off.
Perfectly sculpted organic curves greet me as I slowly descend while light plays off the sides of the riverbank. I follow Gina upstream as small fish that must have arrived from the gulf and stayed in the neighbourhood because they liked the privacy and the schools swim effortlessly beside me.
Gina motions that I should stop using my hands to swim. Properly chastised, I keep my hands glued to my sides and realize I am suddenly in a watery darkness.
I look up to reassure myself, but instead of daylight I see that we have passed into what looks like an underwater cave.
This illusion is created by mangroves that grow along the riverbank and have been ambitious enough to completely cover the surface. From our underwater perspective, though, it looks like we're following the river underground.
As I keep swimming, Gina and Brian remain vigilant to the possibility that I might do something stupid. I, however, am far too awed to do anything but breathe in and out. Thirty minutes later, they haul me up on the muddy bank of the cenote, where I strip off my wetsuit, feeling both exhausted and elated.
"Not bad for a newbie," Gina opines. "In the morning we're diving the gulf. Don't get drunk tonight or tomorrow you'll barf in your mask."