I can’t say I feel more confident knowing that Krack has assisted with hundreds of blackout recoveries, and has passed out underwater six times himself. But I do know he’s taught nearly 6,000 students, including the magician David Blaine, and coached divers to more than 100 national and 20 world records.
The sport is simple enough, as we learn it: a diver descends headfirst alongside a weighted measuring line, kicking hard, then slowly, and then not at all—because by 66 feet, a compressed wet suit has lost its buoyancy and the diver begins to sink; after that, kicking wastes energy needed for the return trip and accelerates the heartbeat, depleting oxygen. Meanwhile, the pressure in the ears feels as sharp as a drill and requires clearing, most often by pinching the nose and blowing.
On the fourth morning, as we head out from the shore of Pu’uhonua o Honaunau—past sunbathers and snorkelers, coral beds and lava flows, damselfish and yellow tangs—it’s not long before nothing but blue lies beneath us. The instructors warn us not to get a number in our heads, but of course we want to reach 100 feet, even though most of us have never before tried going deeper than 30. I think of this goal as swimming the length of a Boeing 737 that has crashed nose-first into the ocean. Setting a depth goal and reaching it might as well be free diving’s narcotic.
If scuba diving is an outward journey—Krack calls it tearing through a forest in a Hummer with the AC on and the windows up—free diving is an inward passage. It’s a lone descent, as you feel your body adapt to the depth. The mammalian diving reflex kicks in: the heart slows, peripheral blood vessels constrict, the spleen compresses and dopes the body with red blood cells.
As I kick down, I’m bubbleless, sleek. A bright metal plate at the end of the line marks 100 feet. A solitary squid watches me descend. I kick and kick, feeling my fins paddle back and forth, through a medium with 800 times the density of air. The water is clear here. I shouldn’t be looking at the plate, but I can’t help myself. I reach and grab it, before turning to head up to the surface. I’ve been sinking, so now I have to kick hard, as I bring my hands together overhead. I’ve slipped from my Zen state. My legs feel leaden, as my diaphragm contracts. What can I do but kick? At 33 feet, I’m aware of my instructor motioning for me to sweep my arms down in a final push. The contractions are worse, but I know I’m not far. So I kick. The air expands inside my mask. It’s possible—and thrilling—to take the minutest sniff. Then I exhale, as I’ve been taught, before breaking the surface, so I can immediately breathe in. Thor takes me through six recovery breaths, aware that 90 percent of blackouts occur after surfacing, and I signal that I’m okay. I look at my gauge, and it reads 102 feet, with an underwater time of 1 minute and 11 seconds—longer than it should have taken, but I’m alive. Floating, I keep breathing in. I’m breathing hard.
Then the instructor asks, “Who wants to go deeper?”