WASHINGTON HEIGHTS (CBSNewYork) — There’s still no sign of a marathon swimmer who went missing in the Hudson River during Friday’s leg of a week-long race.

The NYPD says divers went back into the Hudson at 10 a.m. Saturday to resume the search.

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CBS2’s Aundrea Cline-Thomas reports the swimmer has been identified as 67-year-old Charles Vanderhorst, of North Carolina.

Search and rescue crews launched into the river around 3 p.m. Friday. Chopper 2 was there as they focused their efforts in the area near the Manhattan side of the George Washington Bridge.

The coast guard says Vanderhorst was part of what’s known as the 8 Bridges Hudson River Swim. Organizers say it’s the longest marathon swim in the world.

A kayaker acts as a spotter for the competitors, who swim about 19 miles a day. The coast guard says a spotter became concerned after Vanderhorst did not resurface after going underwater.

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The week-long swimming competition began last Saturday at the Rip Van Winkle Bridge in Catskill, New York.

Friday’s leg spanned from the Mario Cuomo Bridge to the George Washington Bridge.

The final stretch that ended at the Verrazzano was supposed to take place Saturday, but organizers have called it off.

Despite hours of navigating the cold waters of the Hudson, there is still no sign of Vanderhorst.

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Organizers say all of the safety protocols were followed.