The Shelter Island Police Department said a Manhattan man staying...

The Shelter Island Police Department said a Manhattan man staying at a hotel in town with his family was found dead under a nearby dock Wednesday after failing to return from a morning swim. Credit: Randee Daddona

A Manhattan man found dead under a dock after he failed to return from a swim while at a Shelter Island hotel with his family was a standout triathlete who turned his passion for fitness into a career, according to a friend and fellow athletic trainer.

Spencer Korwin, 38, had last been seen about 8 a.m. on Wednesday after he entered the Shelter Island Sound near Crescent Beach from a dock at the hotel, the Shelter Island Police Department said in a news release. Korwin's wife contacted hotel staffers hours later, at which point first responders were activated for a search. The police did not identify the hotel.

His cause of death has not yet been determined, but police described the incident as an "apparent drowning." That came as a shock to John Lippert, the co-owner of SportsLab, a Manhattan sports performance training facility where Korwin was a trainee turned trainer.

"He was a great swimmer," Lippert, 56, also of Manhattan, said of Korwin. "That's why this is such a big surprise to all of us."

As a teenager, Korwin began strength training and conditioning under Lippert. After returning home from his four years at Syracuse University, Korwin returned to SportsLab as a strength trainer.

Korwin was "very dedicated to fitness" and represented Team USA at the Triathlon World Championships, Lippert said. He competed in various other athletic events over the years.

Nearly six years ago, Korwin started his own business, Korwin Health and Wellness, so he had a flexible schedule to become "a real family guy," Lippert said. He and his wife have two daughters, ages 4 and 1.

Lippert described his "very dear friend" as a natural outdoorsman who enjoyed boating, camping and kayaking, skiing and surfing.

"He was the guy his friends would go to if they wanted to take their kids camping or surfing or fishing," Lippert said. "He would basically hold their hand and show them the way."

Divers found Korwin underwater near the same dock he used to begin his swim, the news release said. He was and pronounced dead at the scene.

An investigation remains underway as the Suffolk County Medical Examiner’s Office determines Korwin’s "cause and manner of death," Shelter Island police said. The department does not suspect criminality and believes the incident was "accidental in nature."

Newsday's Robert Brodsky contributed to this story.

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