Yan Fu deserves some of the credit for the marathon sea swimmer Leslie Abigail Hamilton’s groundbreaking lap around Staten Island this summer.

Mr. Fu did not jump in for the 14-and-a-half hour, 37-mile swim in July that earned Ms. Hamilton the distinction of being the first woman to officially complete the route. His role, instead, was to prep the carb powder drinks she gulped down at regular 30-minute intervals and cheer her on from an escort boat.

Still, “I couldn’t have done it without him,” Ms. Hamilton said. That applies to every major swim she’s undertaken since they fell in love in 2018, while competing against each other on glow-in-the-dark dodgeball teams in Manhattan.

Ms. Hamilton, 31, is an accountant and the controller at Garrison Investment Group, a Manhattan private equity fund. Mr. Fu, 35, is a civil rights and employment lawyer who runs his own practice, the Fu Firm, in Manhattan. Both were wearing neon uniforms, per their dodgeball league’s dress code, in September 2017 when they first met on the courts of P.S. 183, a New York City public school on the Upper East Side.

Even so, neither stood out to the other right away. At O’Flanagan’s, a bar they frequented with their separate teams after competitions, “I don’t remember meeting him, and he doesn’t remember meeting me, either,” Ms. Hamilton said.

She had joined to make friends in New York, where she had moved less than a year earlier. That wasn’t hard. “I instantly connected with this group of people,” she said. A connection with Mr. Fu that amounted to more than group attempts to pelt each other with a ball would take a while.

Ms. Hamilton spent her childhood in Charlotte, N.C., with her parents, Douglas and Linda Hamilton, and younger brother, Bradford; all three still live there. Finding a sport that suited her was a process. “I was the kid who was always picked last in gym class,” she said.

Eventually, she tried swimming. At her first practice, intimidated and outnumbered by swimmers who had been at it since preschool, she cried her way through the warm-up. Then, “I fell in love with it,” she said. “It gave me a big sense of purpose.”

She swam her way onto the division three team at Centre College in Danville, Ky., and lifeguarded back in Charlotte to save money for a separate passion: studying abroad. By the time she graduated with a bachelor’s degree in international relations and history in 2015, she had spent terms in Uganda and Thailand.

“I was very go-go-go,” she said, including in the planning of her career. In 2016, she earned a master’s degree in accounting from the University of North Carolina at Chapel Hill. The same year, a job offer from the firm PwC brought her to the Upper East Side of Manhattan, but 70- to 80-hour workweeks during the busy season made carving out time for swimming impossible. For almost two years she stayed out of the pool.

She traces the start of her marathon open-water swims to the same month she met Mr. Fu, September 2017, when she and a college friend, Dana Reynolds, swam a Hudson River 10K from Yonkers to the George Washington Bridge. “It was a gateway swim for me,” she said. Ms. Reynolds got an instant case of the creeps from the murky water, Ms. Hamilton said. But for her it was different. “Part of me was thinking, I could totally do more of this. I was enjoying it.”

That fall, Mr. Fu was starting to feel the same way about his post-dodgeball conversations with Ms. Hamilton at O’Flanagan’s, which has since closed. Born in Xiamen, in Southeast China, he moved to the U.S. with his parents, Zhidong Fu and Wenxiu Huang, when he was 5 so his father could study chemistry as a graduate student.

The family grew with the addition of his younger brother, Andrew Lei Fu, in Washington, D.C., before the Fu family settled permanently in Plainsboro, N.J. (Mr. Fu’s parents, who both eventually earned graduate degrees in computer science and worked in that field, now live in Alpharetta, Ga.). At George Washington University, Mr. Fu double-majored in economics and political science, graduating in 2010 with a bachelor’s degree.

Three years later, he earned his J.D. degree from Columbia. Civil rights law was a passion in addition to a career path. He serves on the board of the Sonya and Celina Sotomayor Judicial Internship Program, a nonprofit that matches students from underrepresented backgrounds with judicial internships.

Glow-in-the-dark dodgeball, also called black light dodgeball, held the same appeal for Mr. Fu as it did for Ms. Hamilton: It was a fun, easy way to be social in New York City. When he found out the team he joined in 2016 met for postgame karaoke, it became even more appealing.

“I can’t carry a tune really well, but doing karaoke to rap songs” — hits by Eminem, Jay-Z and 50 Cent top his repertoire — “is one thing I’m pretty good at,” he said. (dodgeball buddies tend to agree. “Yan is a song slayer and mic master who kills it every time,” said Tristan White, a friend and former teammate. The league paused for Covid in March 2020; play has not since resumed.)

Ms. Hamilton and Mr. Fu were both on dating apps, but unenthusiastically, when, in the early months of 2018, she began to notice he was paying more attention to her than his other female teammates. But “it was one of those things where it was like, I’m going to wait for him to make a move because I wasn’t sure,” she said. Around Valentine’s Day, she thought he was going to kiss her. “But he chickened out.” That was disappointing.

By mid-February Mr. Fu, who lived in East Harlem, had summoned the courage to ask Ms. Hamilton, who lived in Hell’s Kitchen, if she’d like to go out with him sometime. She said yes. On Feb. 24, 2018, they went for a bacon tasting at the now-closed Bar Bacon. There, “the conversation was a little more formal,” Mr. Fu said, meaning they kept dodgeball talk to a minimum in favor of deeper subjects.

Both left thinking the stars had aligned for romance. Still, “again he chickened out to kiss me,” she said. This time, he had good reason. “I liked her so much I didn’t want to mess it up,” he said.

On their second date, a few days later, he was ready. After 1 a.m. hot dogs at Rudy’s in Hell’s Kitchen, he pulled a Chapstick out of his pocket. “I thought, this time he’s going to do it,” Ms. Hamilton said. She was right.

By spring, they were a couple. By the following year, Ms. Hamilton was planning more complicated and challenging swims, and Mr. Fu was learning how to be her chief supporter. They moved to a new Upper West Side apartment together in June 2019, shortly after her first official long-distance swim, a 13-mile trek down the Hudson River.

Focus, Ms. Hamilton said, is important in the water. Run-ins with sharks and stinging sea lice haven’t deterred her. She admits to having trouble concentrating, but mostly on land, when she started to fall in love with Mr. Fu.

Now, from his frequent position in the escort boat, he’s a calming influence. “In the same way I appreciate the scenery like the ocean waves around me, or the glow of the Verrazano Bridge, or the apocalyptic-looking industrial tankers in the Arthur Kill, I appreciate and feel secure knowing I have him on the adventure with me,” she said.

On Feb. 12, 2022, they committed to a lifetime of further adventures as a couple when Mr. Fu proposed with a diamond engagement ring at Karaoke Duet 53 in Hell’s Kitchen.

On Aug. 5, Ms. Hamilton and Mr. Fu were married at SouthPark Church in Charlotte by Kyle Thompson, the senior pastor, with just their parents and brothers watching. On Sept. 23, they invited 150 friends and family members for a second ceremony led by Mr. White at the Grandview in Poughkeepsie, N.Y. The couple chose the venue for its views of the Hudson River, more familiar to both at water level.

Ms. Hamilton, in a floor-length wedding gown designed by Tony Ward, walked down an outdoor aisle with her father to a trellis strung with fall flowers; guests had been given ponchos to stay dry as light rain fell from lingering tropical storm Ophelia. Mr. Fu met her in a black Calvin Klein tuxedo and gold bow tie. Dodgeball teammates dominated a 16-member wedding party.

In handwritten vows, Mr. Fu told Ms. Hamilton he had known for years she would be his life partner. “I knew during the countless kilometers, coldest waters and double practice days,” he said. Ms. Hamilton, in her vows, said Mr. Fu has all the qualities she wants in a husband, and many she didn’t realize she needed. “I promise to always support you in your passions and pursuits, and never take for granted your constant support of mine,” she said.

Mr. White closed the ceremony by asking both if they promised to “duck, dive, dip and dodge” for the rest of their lives, a reference to the 2004 movie “Dodgeball: A True Underdog Story.” When both said they did, bridesmaids pumped their bouquets, groomsmen whistled and cheers rang out for the start of the couple’s new marathon journey, sealed with a kiss.

ON THIS DAY

When Sept. 23, 2023

Where The Grandview, Poughkeepsie, N.Y.

Dance Floor Dodging At a cocktail hour and reception under an outdoor tent at the Grandview, Ms. Hamilton and Mr. Fu surprised their guests with a record-scratch moment during their first dance, to Ed Sheeran’s “Perfect.” A minute in, the song was replaced by Smash Mouth’s version of “I’m a Believer.” Both sides of the wedding party rushed to the dance floor to play a round of dodgeball; Mr. Fu was the last player standing.

Fall Flavors Cocktail hour nibbles included a Thanksgiving panini made with turkey, Brie and cranberry dressing and butternut squash soup. Later, the couple cut a wedding cake decorated with mini dodgeballs made of maraschino cherries.

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