In the late afternoon, after several more rapids, we reached the Supai Ledges, just as an impressive September squall began pattering raindrops on the flat rock shelves. The patter turned into a full-on deluge, and everyone scurried to set up tents, and some of the boys set up camp in caves between the overhanging ledges of rocks. As sheeting rains cascaded down the canyon walls, it felt like something of a celebration. After a successful first day on the river, most of us stripped down and stood beneath the superheated waterfalls pouring off the cliffs, showering in the warm wash, laughing. The rain came down so hard, I could hear chunks of earth falling from the walls across the river and splashing violently into the water.

I awoke to the morning sun drying the tent and the rock shelves we’d camped on. As we launched our kayaks, the river smelled of earth, and the water felt textured, thick with silt. That silt was already covering my face, in my mouth and eyes, in my underwear and clothing. “The Colorado River has the highest percentage of silt to water of any other river in the world,” Harlan said, “and after it rains, it turns to sludge.” Rob confirmed that the water had gone from clear, where we’d started near the Glen Canyon Dam, to “chocolate milk.”

Shortly, we came to House Rock Rapid, the first considerable rapid of the canyon. It was rated about a 7 on the Grand Canyon 1-to-10 scale. “Stay right, stay right,” Harlan warned me as we drew near. But his voice was garbled and choppy over the radios, cutting in and out. Great, I thought, feeling frustration and fear expanding inside me. The first big rapid and the radios are already failing! “Large hole on left! Hard right!” I could barely make out the words through my earpiece.

The force of the water and lack of clear communication put me on the defensive. I tensed up and leaned back, my head cocked awkwardly to the side as I strained to hear. The movement became violent, abrupt, tossing me up and down. Amid the tumult, the paint-shaker motion, and the boomeranging barrage of river noise, I recovered and did what Rob and Harlan had taught me. I paddled hard.

“Charge!” I finally heard Harlan say, muffled and distant. I slammed into a cold wall of water. A powerful lateral wave lurched me sideways as the world tossed and turned in dizzying confusion. “Brace left! Brace left!” Harlan squawked, and I righted myself, half hearing “Charge!” I dug in, air, spray, and sound engulfing me. “You’re good, you’re good,” Harlan’s voice crackled as I bounced through the last set of tail waves and eddied out, slumping in relief.