What initially had been a search became a "recovery effort," the Coast Guard said.
The unidentified swimmer was participating in a 15.7-mile next-to-last leg of the “8 Bridges Hudson River Swim” -- which began at the Tappan Zee Bridge and was headed to the George Washington Bridge -- when a spotter saw him go under and not reappear near the foot of the "Little Red Lighthouse" at Fort Washington Park, the U.S. Coast Guard said.
The Coast Guard joined the NYPD Habor Patrol Unit and the FDNY in the search, which stretched across the Hudson between Washington Heights and Fort Lee.
The competition, which was to cover 120 miles over seven days, began June 8 at the Rip Van Winkle Bridge, which spans the river between Hudson and Catskill.
Organizers cancelled Saturday's final leg from the GWB to the Verrazzano Narrows Bridge between Staten Island and Brooklyn.
"On behalf of New York Open Water, it is with great sadness that we report the loss of a swimmer today on Stage 6 of the 8 Bridges Open Water Swim," they said in a statement.
"We can confirm that all swimmer safety protocols were in place and that the NYPD was escorting the field," they added. "We will continue to work closely with the authorities and will provide updates as they become available.
"Our thoughts are first and foremost with the swimmer's family. In respect for their privacy, we are declining to name the swimmer at this time."
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