The Captain Khlebnikov icebreaker carrying 101 passengers got stuck in the ice earlier this week near Snow Hill Island in the Weddell Sea off Antarctica. It has taken the ship five days to free itself, Fareastern Shipping Co. spokeswoman Tatyana Kulikova said Friday.
She said it would now take the icebreaker three more days to return to Ushuaia on the Argentine coast - a full week after it was supposed to arrive.
Kulikova said Antarctic weather is unpredictable in the early spring. "It's impossible to avoid worsening ice conditions with rapidly changing weather," she said.
"There was nothing extraordinary in those conditions," she said, adding that the ship's captain has 20 years of experience.
Officials said the passengers never were in any danger.
"It's part of Antarctic tourism - we always warn passengers about possible delays," Vyacheslav Naganyuk, the head of icebreaker fleet at the Fareastern Shipping Company, said in a statement. "Tourists witnessed real difficulties of shipping amid the splendor of Antarctica, and I think they will keep special memories of it."
The cruise was advertised as a unique opportunity to watch emperor penguins in their natural habitat. The Finnish-built icebreaker has been used as a cruise ship for several years and carries two helicopters.
Kulikova said the icebreaker is scheduled to make another Antarctic cruise in the fall.
Two-week tours aboard the Captain Khlebnikov to see emperor penguins range from $13,890 (euro9,350) to $22,690 (euro15,280) per person.