A Revere man reportedly passed away after falling overboard from a sailboat in the waters off of Marblehead Saturday afternoon.

Salem Assistant Harbor Master Patrick Mulligan identified the man as Joseph Sampson, 63, of Revere on Monday morning.

According to Mulligan, area emergency responders received an alert around 2 p.m. Saturday that a man had fallen from a sailboat.

Passengers aboard the Boston Yacht Club's Race Committee boat, he said, were the first to notice that something had gone wrong.

"They witnessed him fall off the sailboat and then they immediately went over and were able to retrieve him from the water," Mulligan said.

Although he said it appeared Sampson suffered a heart attack, Mulligan said it remains unclear what caused him to fall into the water.

Mulligan said the Salem Harbor Master's boat intercepted the race committee's vessel and escorted them as they rushed Sampson to a waiting ambulance on State Street. He was reportedly taken to Salem Hospital.

Mulligan said Sampson was a volunteer crew-member.

Sampson was a "great, highly-experienced sailor," according to his dear friend Marty Browne, of Newton, who reached out to Marblehead Patch after our original story ran last night.

Browne said Sampson grew up in Hyde Park and started sailing at Community Boating, on the Charles River when he was 11 years old.

"He rejoined Community Boating, in 1970, and that was when we met," Browne said in an email. "He started serious ocean racing in June 1977 when he sailed in the first Marion-Bermuda Race."

Sampson, Browne said, recently began sailboat racing again following the passing of his wife.

"In the 80's, Joe and his late wife, Janet Kennedy Sampson, bought the J-30 MISTRAL. They raced MISTRAL in Marblehead PHRF races, successfully, for many years. After they sold the boat, Joe stopped racing,  but he resumed racing in the summer of 2011 after his wife passed away," Browne said.

Marblehead Patch will be posting additional information as it becomes available.