It was what you’d call a dog day of summer. Back then that meant anything above 85, not the triple-digit temps we have now. We’d sit along the edge of the dive well, tongues dyed raspberry push-pop blue, legs dangling into the water waiting out those wretched fifteen minutes between lifeguard whistles. The pool would empty out but for old Ms. Barb, with her hot pink floral swimsuit and matching cap, swimming lap after impressive lap of unhurried sidestroke. Ms. Barb disliked getting her head wet and was pretty militant about us kids not splashing into the lap lane. But, over in the dive well, safe from Ms. Barb’s wrath, it was like the Olympics of cannonballs, dad-bod division. We’d rate the Cannonball Dads in cheers, based on splash size, based on how effectively they cooled us off, pool water splashing onto red, white, and blue popsicles that dribbled down our forearms as we took chlorine-soaked bites. The best Cannonball won a six-pack from a community cooler.

Dad never did the cannonball contests. Too skinny, too academic. Also, he didn’t like the pool. It was Mom who shoved our towels and goggles onto us boys and pushed us out the door so she could do mom things with her favorite soap on. The other Dads sat around talking sports, passing around beers and ignoring their children. They left packs of Marlboros on their towels. We stole cigarettes but never actually smoked them. Dad sat there grading papers on the picnic table in the shade. The thought of him socializing with the Cannonball Dads made my stomach do its own sort of cannonball.

The Cannonball Dads, though. There was Eleni Kastinakis’ dad, with a carpet of black hair from chin to belly button, fat rolls bouncing as he got a running start before jumping and tucking his knees. Kristen Carr’s dad, with his dog tags and “Semper Fi” tattooed in Old English across his traps, forward flipping before spreading eagle to belly flop. Colin and Carter, the twins, their dad thought he was so funny, swinging his arms in maniacal circles mid-jump, though the splash itself sucked. Everyone knows the power comes from the butt.

That day, maybe the heat got to him. Dad took off his glasses and polo shirt, the one embroidered with the emblem of the college where he was teaching summer school, and walked over to the diving board. All eyes were on him for a second before the whistle blew, and the kids dispersed, like cockroaches in the spotlight, shrieking as they shattered the shimmering surface of cool relief. Only I remained, watching Dad. Watching him climb the three steps of the ladder. Watching him walk to the edge of the board. Watching him hold his arms out wide, swing them above his head and back down to get airborne, tuck his knees and strike the water with what could only be described as a blurp.

The shame hit me later, forceful, like Mr. K’s winning backflop. It was the way Dad kept talking about it afterward. “Did you guys see my cannonball?” he kept asking us. At home, he told Mom, “yeah there were these cannonball contests during adult swim and I took the final jump.” I felt sorry for him even though you’re not supposed to feel sorry for your dad. But that didn’t last long, since that was the day Dad walked out on us. Back then I thought he was punishing me for feeling sorry for him, for being embarrassed.

I looked him up, later. He seemed happy, with forgettable-looking stepchildren, family portraits on the beach, one arm draped lazily around a new wife. Apparently he does triathlons now, and coaches girls’ softball. Better than coaching swim team, I guess.

I lost track of the cannonball contests. I aged out of expressing unabashed joy in public, then outgrew the pool altogether. But I’ve returned, as we all seem to do, and my body bristles in that charged silence in the moment after the whistle, while our collective conscience registers that it’s time. Tiny feet splashing and high-pitched hoots from a chorus of deceptively small bodies. My own kids looking at me, sugar-loaded innocence in their expectant faces. And that other feeling, long banished, that such joy will bring everything else, the shame, the abandonment, threatens to erupt. It’s only now, in long overdue hindsight, that I marvel at the Cannonball Dads’ confident abandon. To belly flop, wildly and purposefully, for the sole privilege of receiving cheers from sunbaked neighborhood kids.

I grasp the handrail, place a tentative foot on the lowest rung. My vision clouds, but I continue up. And then I run. Because that’s the thing about cannonballs. They have to hurt to be good.