FOR YEARS, my mother hauled me to St. Mary’s Parish. Sunday mass was a habit for most Boston Catholics, but one she, and I, would eventually shed. On the church’s brick steps, I dreaded the misery that awaited me on the pew, granite-hard under my scrawny child’s body. I knew the purpose of my presence was to feel small, earthly, and sinful. “Let us proclaim the mystery of faith,” the pastor commanded.

Today, I enter another temple at 9:00 a.m. Other days, 9:30. Like mass on Sundays, adult lap swim at the Northwestern Connecticut YMCA is rigidly scheduled. Unlike at church, my attendance at the pool requires a reservation.

At the edge of the pool, I shiver, adjust the leg bands of my swimsuit. I regard the water with a similar reluctance to the one I felt outside of St. Mary’s. At the abyss separating the weighted and the weightless, I choose the latter and dive in, swim off the shock of cold, skim along the water like a tropical fish.

Small, earthly, and sinful. I am all of those things, but here I am buoyant and unencumbered. Not bound by gravity or guilt. Mind blank, body unclenched. Outside, I am capable of parceling out my own shame; here, no men in cassocks carry out that terrifying deed.

I entertain a certain precariousness: breath gulped; breath held. Chlorine in my nose, an anachronous chemical intrusion. Some flame-red pain in my left shoulder that, if I keep swinging the corresponding arm, will undergo a softening. Windmill the biceps, flutter the feet, move in automatic rhythm. I could be flying or ascending into heaven. I follow the painted line, hear the splashes and the echo of the lifeguard, chatting. I anticipate touching the end of the pool, the flip turn, the balls of my feet giving a satisfying push off the cement wall.

I am in procession as if practicing a ritual. An instinct, like the cadence of prayers I almost never recite. Up and back, up and back. At last, I leap, twisting my body out to rest on the lip of the pool. I peel the goggles from my face.

Shall we proclaim the mystery of faith? A basin, filled by water from melted glaciers or summer cloudbursts that caused the local reservoirs to gush and rage. Seventy-one percent of Earth’s surface that I inhabit only a few hours a week. This crisp, chlorinated YMCA water. It renders me clean.