Marilyn L. Diamond, the Northeast service-company owner known as “The Pool Lady,” died Nov. 14 at her Atlantic Beach, N.Y., home after a brief battle with cancer. She was three weeks shy of her 71st birthday.

Diamond — one of the first females in the male-dominated service industry — is remembered as a pioneer in her field. She also distinguished herself as only the second Northeast Spa & Pool Association chairwoman, in 2001. Before that, she had served at the helm of NESPA’s Long Island Chapter.

Born in Moscow, Idaho, on Dec. 2, 1938, Diamond graduated from Northwest Nazarene College in Nampa, Idaho, with a degree in education. Her passion for teaching — and learning — would play a major role in her own professional growth as well as that of the industry.

Her young adulthood was an eclectic one and included a stint teaching English in Japan, as well as a career as a flight attendant. Eventually, she left the airlines to raise her children, while continuing to teach on occasion.

Her involvement in the pool industry began as a hobby. Initially, Diamond and her husband maintained pools for family and friends. At that time, neighborhood children would call out “The Pool Lady is here!” upon seeing her. The name stuck.

In 1981, her husband died, leaving her a single parent. “She was a stay-at-home mom and, after my father passed away, she needed income,” said her son, John Diamond. So she turned her hobby into a full-time pursuit, and opened The Pool Lady Inc.

“She just said, ‘OK, this is what I’m going to do,’” John Diamond said. “She [learned] how to do the chemicals better, and made sure she knew how to do the cleaning and repairs. She taught herself.”

Diamond’s company eventually became a 120-account operation with several employees. In spite of her illness, she remained active in The Pool Lady Inc. through the end of this summer. Her sons John and Matthew Diamond will continue the business.

The Pool Lady was known for putting an emphasis on customer service. In addition to cleaning and repairing the pools, Diamond would do little extras such as hosing down decks and helping customers prepare their backyards for the winter. She insisted her employees do the same.

“She never was afraid to get her hands dirty,” said Paulette Pitrak, NESPA’s deputy executive director and a close friend of Diamond’s. “She had that Western personality, that cowboy independence.”

Diamond brought her customer-first sensibility and desire for knowledge to her role as NESPA’s chairperson. “Her big push was always education,” said John Romano, president of All American Custom Pools and Spas in Norwalk, Conn. “She was always in the midst of, or helping organize, something.”

She also was known as a compassionate leader. “She was the kindest and most thoughtful person you would ever want to meet,” Pitrak said. “She really cared about her officers and making things pleasant for the volunteers, and [ensuring] the staff was given kudos.”

While Diamond was considered a trailblazer for women in the industry, she also had a strong sense of history and tradition. “I remember she tried to get every past president of the Long Island Chapter to a meeting,” said George Kazdin, president of Kazdin Pools & Spas in Southampton, N.Y. “I think when she was show chairman in Atlantic City, she got every past president of NESPA up there. She was always very cognizant of the work that went before her.”

In addition to her sons, Diamond is survived by a daughter-in-law and three grandchildren.