The Canadian government says a yachting accident off the coast of Nova Scotia that has left one dead and three missing is being treated as a human smuggling attempt.

Search-and-rescue crews have found no sign of three missing people amid high seas and bad weather after the SV Tabasco 2 ran into mechanical trouble.

Nine people were aboard the ship in total. One is confirmed dead, while five others were rescued from the yacht, which floundered in the frigid Atlantic Ocean Monday night.

Public Safety Minister Vic Toews said some of the survivors have asked for refugee status.

"I thank the men and women of the Canadian and U.S. (search-and-rescue) teams who put their lives at risk to make this dangerous rescue," Toews said in a statement.

"This tragedy highlights the need for speedy passage of the Protecting Canada's Immigration System Act. There is an enormous and unnecessary risk involved with the act of human smuggling. Our government's message is clear to those contemplating a human smuggling operation -- don't do it."

Officials believe the three missing men were wearing life-jackets but not survival suits when they went overboard at about 12:30 a.m. Survival suits would have helped protect them from the frigid Atlantic waters.

A Canadian Forces Cormorant helicopter and Hercules search-and-rescue aircraft, as well as a Canadian Coast Guard cutter are all involved in the search.

Capt. Bertrand Thibodeau, a pilot of the Hercules, said the search conditions are some of the harshest he's seen, with five-metre swells and winds of up to 90 kilometres per hour.

Sgt. Norm Penny said the rescue operation involved "the worst vessel I ever had to be inserted on and take people off of."

"You're probably dealing with wave action probably similar to a three-storey or four-storey building," Penny told CTV Atlantic. "Winds of (90 km/h) at night, with snow squalls all around us."

Search officials said the people rescued aboard the yacht seemed to be in their 40s and were from Russia, Ukraine and Georgia.

The yacht first ran into trouble about 150 kilometres south of Cape Sable Island, said Capt. John Pulchny, spokesperson for CFB Greenwood, where the search crews are based.

"Luckily there was a tanker ship called the Hamburg that was on scene in the area," Pulchny said. "They were able to rescue three of the nine and when the Cormorant arrived on scene they were able to rescue another three."

Of the three sailors picked up by the Cormorant, two were taken to hospital in Yarmouth, N.S. and are in fair condition, but one died en route, Pulchny said.

The three who were picked up by the tanker were transported to Saint John, N.B.