A day after their rescue, South Korean President Roh Moo-hyun telephoned the research team leader on Tuesday in Antarctica to praise their survival skills and extend condolences for one member lost at sea when their boat capsized.

"I highly praise the courage and will the seven members showed in overcoming the difficult situation," Moo-hyun said.

International search parties had scoured the waters for the missing scientists, since a first group of three disappeared on Saturday while they were returning to base in a rubber boat, amid heavy snow and strong winds. 

A five-member team sent out on Sunday to look for them also disappeared that night in the bad weather.

"I highly praise the courage and will the seven members showed in overcoming the difficult situation"

Roh Moo-hyun,
South Korean president

Four of those men swam to shore and sought shelter in a hut, warming each other by huddling together and eating snow.

One researcher, Chun Jae-kyu, 27, drowned before making it that far, according to Lee Yoon-ho, an official at the government's Korea Ocean Research and Development Institute. 

The survivors were found the following day by a Russian search team and were transferred to a Chilean air force hospital. 

The three other researchers also swam to shore and were rescued by the Chilean air force on Monday night, 52 hours after they went missing.

They had survived by eating chocolates and snow to ease their thirst. South Korean officials said they were believed to be in stable condition. 

The researchers were stationed at South Korea's Sejong Station, on King George Island at the tip of the peninsula stretching towards South America.

South Korea opened the base in 1988.

Besides 15 researchers based there on a one-year assignment, a small group of scientists visited the base for two-month research stints.