BILLERICA, Mass. — Roy Nagy and his wife wanted to hear the wind and waves when they fell asleep on the Royal Caribbean cruise in late September. Instead, around 4 a.m., they suddenly woke up to cries for help.

" 'Hey! Hey! Help! Help!' " Nagy recalled hearing. "They were yelling and whistling, and we jumped up to run out to the balcony. If my wife hadn't opened the door, I'm not sure we would have heard them."

Nagy and his wife, Kendra, couldn't see anyone in the dark Caribbean waters, but it sounded like people were in distress down below. As the ship continued to move toward St. Martin and the voices became softer, Nagy concluded that people were overboard.

He called the ship's main desk, as did two other passengers. Capt. Tore Oslen stopped the ship, issued an alarm throughout the entire ship that someone was overboard, and sent out a boat to search the water, and the ship's crew rescued three Americans who had been in the water for about 10 hours.

"They shined a spotlight in the water, and we could see a person waving his arms frantically, so we were thrilled that somebody was going to be rescued," Nagy said. "They were without food, water and floating without lifejackets for hours, so they were in real tough shape."

The three Americans who were saved had capsized their speed boat 10 hours earlier. They had capsized off the coast of St. Thomas while heading to St. Croix; the bottom of the speedboat had filled with water and capsized just as it was getting dark.

Once onboard, they received food, water and medical treatment.

"We met them the next morning, and they hugged us and thanked us, saying we saved their lives," Nagy said Wednesday at the Billerica Boys & Girls Club, where he's the executive director. "It was very emotional for all of us. I'm just so happy these guys survived.

"It's something you won't ever forget," he added. "It makes you realize how fragile life can be."

Nagy and his wife became celebrities during the rest of the cruise, he said. The captain invited them for a visit, telling them of past rescues and thanking them for alerting the ship. Oslen emphasized that the three men would have died if they hadn't sent an alert, according to Nagy.

Crew members brought them an endless supply of wine bottles and chocolate, and would constantly hug and thank them. Passengers kept on asking what happened.

"We wanted to go away and relax, but it kept coming up," Nagy said. "I feel the emotions every time I tell the story. It just gives me goosebumps every time."

Billerica resident Cosmo Cavicchio, who is on the Boys & Girls Club board of directors, said he wouldn't expect anything less from Nagy and his wife.

"They've just dedicated their lives to being good people and always giving themselves to other people. I'm proud to know them," Cavicchio said. "It was amazing to hear their story. They're heroes to all of us."