Any time my friend Rob Raker stopped by the house, both my son, Arjun, and my daughter, Emma, would grin excitedly, shout out “Uncle Rob!” and run up to greet him. I had first met Rob in Antarctica, where I was climbing Vinson Massif and he was part of a production crew filming a television show. We connected again on another adventuring trip, three years later, and became fast friends both on expeditions around the world and back home in Colorado, where we both lived with our families.

Rob would take Arjun out in the yard to kick the soccer ball around or play catch. Once he showed up with a Red Raptor Osprey Sport Kite, and we all went to the top of a nearby mesa where the wind was gusting hard. He taught Arjun how to play out the kite strings as he ran into the wind, and how to make the kite perform acrobatic moves, climbing and diving and inverting. Often, he’d arrive with little gifts in hand like a feather from a prairie falcon, a chunk of fool’s gold, or the vertebrae he’d found of a small animal. He’d have the kids explore the skeleton and make conjectures based on their observations. “Exactly,” he’d say when they were onto something.

Rob also loved to go rock climbing, skiing, hiking in the foothills, and whitewater kayaking. I told him that kayaking intrigued me and that I’d taken a class in a pool to learn to roll, but I’d never quite gotten it.

“I can teach you to roll in two hours,” Rob declared.

I privately wondered how that would work, but I had learned by now not to doubt this guy. When you flip a hard-shell kayak—either by getting hit by a wave, ramming into a rock, or just by tipping over—you are still sitting in the boat, but you are now upside down underwater. The “roll,” simply stated, involves going from being upside down to being right-side up. But being blind, learning how to pull off the move was really difficult. I couldn’t just watch a video, memorize the moves, and copy them. It was really hard to visualize the big picture. While underwater, I was disoriented, and everything was confused and backward.

“I think this will be an interesting challenge for both of us,” Rob said.