Some quick action and bold navigating by a charter fishing captain on Friday likely saved the life of a New Jersey man who fell from his boat into rough seas off Wasque Point on Chappaquiddick. The man was not wearing a life jacket at the time and had to tread water for close to a 30 minutes before being rescued, authorities said yesterday.

New Jersey resident Michael Prigoff was fishing off Wasque Point around 1 p.m. when he reportedly fell over the side of his 21-foot Triton Outcast. According to several eyewitnesses, the boat's engine was in drive at the time and the vessel continued to circle the area with no one aboard.

The area where Mr. Prigoff fell into the water is a riptide-swept waterway between Chappaquiddick and Nantucket famed for bass and bluefishing. Marked by two buoys well known to sport fishermen, the area serves as a navigable entrance way to Muskeget Channel. Some fishermen call it the vortex, because the bottom rises up unusually close to the surface.

The sudden rise in the bottom and the tides cause the waves to collide from all directions, sometimes explosively.

The first person to spot Mr. Prigoff was Jaime Boyle, captain of the charter fishing boat Boylemaker, who saw a boat tacking a strange course through the rips.

"I looked out and saw a boat doing doughnuts, and I'm like, there's nobody on that," Mr. Boyle said yesterday, recalling the events of the day.

At first, Mr. Boyle didn't see the man who had fallen from the boat, although another charter captain noticed him and called the U.S. Coast Guard for assistance. At the same time, Mr. Boyle got on the radio and asked for help from any other captains in the area.

One of the captains who received the call was William Hatch, skipper of the Falmouth-based Machaca, a 31-foot twin diesel fishing boat. Mr. Hatch had a full crew of customers on board at the time, but quickly responded to the area to see if he could help.

When Mr. Hatch motored closer he saw Mr. Prigoff treading water and realized there was no time to spare.

"He was in bad shape. You could see it in his eyes, he wasn't going to able to hang on much longer," Mr. Hatch said.

The water temperature was about 60 degrees at the time, and six to eight-foot breakers were crashing around Mr. Prigoff's head.

Mr. Hatch realized he had to act quickly to save the man's life, but had to consider several other factors: the crew of paying customers on board, the shallow water, the breaking waves and a thick fog that had descended in the area. Tides at Wasque run around four knots, and the wind speed at the time was around 20 knots.

"I was worried about several things, like whether I might bottom out. Then there was always the risk of the boat rolling over when we got close [to Mr. Prigoff]. But I talked to the passengers and they said they were all for it; they wanted to help," Mr. Hatch said, adding:

"In the end we felt it was the only choice; if we bent a propeller or broke a shaft it could be replaced. There wasn't going to be a second chance for this guy."

A former Vineyard resident who has been fishing at Wasque for years, Mr. Hatch used his knowledge of the area to approach Mr. Prigoff and throw him a safety ring. Although he had been treading water for 30 minutes and was likely suffering from low body temperature, Mr. Prigoff was able to get a hold of the ring, and the crew of the Machaca were able to grab him and slide him in through the tuna door on the transom.

The crew of the Machaca covered Mr. Prigoff with blankets and elevated his feet. He was then transported to Memorial Wharf in Edgartown where he was placed in an ambulance and transported to the Martha's Vineyard Hospital. He was treated for minor hyperthermia and released later that day.

Although Mr. Prigoff had been saved, there was still the matter of saving his boat, which continued to motor in circles at harbor speed. Mr. Boyle said he saw another boat pull alongside the unmanned boat and a man hopped aboard and brought it under control, a little like a cowboy corralling a runaway carriage.

"It was quite a feat," said Mr. Boyle of the unknown person's heroics. "That boat was still going up and down. It was a good maneuver - I was impressed."

Mr. Prigoff reportedly returned to Edgartown harbor later that day to claim his boat. Mr. Hatch said Mr. Prigoff said little after he was pulled from the water, but was in no condition to offer thanks. "I think he was in shock a little," he said.

A spokesman for the U.S. Coast Guard said a rescue boat and helicopter were dispatched out of Woods Hole, but were recalled after it was reported that Mr. Prigoff had been rescued.

Edgartown harbor master Charles Blair, who responded to the call for help, praised Mr. Hatch and the other charter captains for their quick response and daring rescue. If they hadn't arrived on the scene when they did, Mr. Prigoff would likely have drowned.

"I don't think he would have lasted more than ten minutes longer in that water; probably not even five minutes. It was a Good Samaritan moment," Mr. Blair said.

Mr. Hatch brushed aside the notion he had done anything heroic. In his mind, he did what any other captain would have done.

"It's an unwritten rule of the ocean that you look out for other sailors and help out when and where you can. I only hope that some other captain or fisherman would do the same for me," he said.

Tom Dunlop contributed to this story.