What to Know A state police diver recovered the body of a 21-year-old man who fell overboard from a party cruise ship near Peddocks Island, near Hull, MA

The Plymouth County District Attorney's Office identified the man as Aaron DiBella, 21, of Peabody.

State police detectives are leading the investigation.

Massachusetts State Police recovered the body of a man who went overboard during a cruise in the area of Peddocks Island near Hull on Saturday night, and a company official says the incident was preceded by "horseplay aboard the vessel."

On Sunday afternoon, the Plymouth County District Attorney's Office identified the man as Aaron DiBella, a 21-year-old military veteran from Peabody. State police found DiBella in the Fore River Channel in Weymouth. A medical examiner will determine the exact cause of death.

According to the U.S. Coast Guard, the Provincetown II, a ferry that goes between Boston and Provincetown, reported a man overboard to watchstanders at Sector Boston at 8:30 p.m.

NBC10 Boston spoke with one of DiBella's friends who was with him Saturday night aboard the "Get Lei'd" party cruise.

"Came back from the bathroom, he was just being wild. Hung off the side and fell," Jake Langlois said.

Langlois says they were celebrating a friend's birthday when the 21-year-old fell into the water. Langlois says he tried to jump in the water to save DiBella but that the crew on the boat stopped him.

"He went under and I never saw him again," Langlois said.

DiBella's body was found four hours later.

"When the water starts to get a little bit colder, your time of survival goes down significantly," said Lt. J.G. Lucy Daghir with the US Coast Guard.

In a statement released by the cruise company prior to identification of DiBella, Bay State Cruise Company officials said the man was "engaging in horseplay" aboard the vessel before falling in. The company's owner says they put a spotlight on DiBella in the water and threw several life rings landing feet from him.

"He kept swimming towards it. He couldn't swim any longer. I think he got like too cold," one witness said.

A crew member jumped into the harbor but couldn't reach DiBella.

Langlois says he wishes he had a chance to save his friend.

"All of us did. There's nothing we wouldn't have done. Just wouldn't let it," he said.

"The tragic and overwhelming sadness that has swept through all of us; our crew, our staff - everyone associated with our company – has left us without adequate words to express just how sorry we are for the family and friends of the gentleman that went overboard," said Bay State Cruise Company’s owner, Michael Glasfeld. "We had him located and illuminated with the ship’s spot light, the several life rings were within just a few feet of him, and a crew member was additionally in the water also within five feet of him to assist."

Officials have not determined exactly what happened but said they are investigating how DiBella ended up off the boat and in the water. Authorities said a security guard from the cruise ship went into the water to try to save DiBella but couldn't reach him. DiBella submerged beneath the water and didn't resurface, police said.

In the company statement, they reported that a crew member first saw the man "engaged in a type of vertical push up from the bulwark of the vessel." The crew member told him to climb down. They said the man complied but then "started in on an even more dramatic form of dangerous play,” according to the statement.

“To our passengers we say, we so sincerely regret that your night on the water should be marked by such tragedy. To our crew, we say, bless you for your efforts and commitment to your training, and, to the family of the lost passenger, there are no words – none – to convey our deepest and most sincere sympathies. We are heartbroken,” according to the statement.

One witness further described the incident.

"I was standing outside when it happened. They rushed us all in and he was floating in the water. The crew shut all of the doors and wouldn't let anyone outside," the witness said.

According to the witness, the man was struggling in the water.

"He went under and then we didn't see him again. There were a lot of event staff trying to take care of it, but I don't think they got to it as fast as they wanted to," said another witness.

Some people say they saw the man in the water for five to 10 minutes before it seemed he could no longer swim.

State police divers recovered the man's body at about 1 a.m. Sunday following a joint search by the Coast Guard and Environmental Police.

State police are leading the investigation.

DiBella's family tells NBC10 Boston that they have questions for the cruise company, including how they train their employees.