A good Samaritan pulled the victim's body from the water after the boat overturned near Keyport around 10 a.m., and immediately began CPR, reports say.
There were no other occupants on the 21-foot boat.
A Coast Guard Station Sandy Hook 29-foot response boat crew arrived on scene within 10 minutes.
The victim was transferred to the Coast Guard crew, who continued CPR while en route to Monmouth Cove Marina.
CPR was continued while en route to the Monmouth Cove Marina, where the individual was turned over to EMS.
The victim was pronounced dead by EMS and the vessel sank in 30 feet of water, the Coast Guard said on Twitter Saturday.
Coast Guard crews from Station Sandy Hook and Station New York were assisted by the New Jersey State Marine Police, New York City Police Department Aviation and New York City Fire Department Marine.
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