Since Tuesday, an Australian fishing boat with 27 people on board has been stuck in thick ice in the Antarctic. The United States sent an icebreaker on Wednesday to rescue the boat and crew.

The Antarctic Chieftain hit 10-foot-thick ice, which caused major damage to her propeller in the McMurdo Sound, located in the Ross Sea in southern Antartica on the Ross Ice Shelf. Les Scott, the managing director of Australian Longline, reported, “underwater inspection showed three of the four propeller blade tips were damaged.” Thankfully the crew has not been harmed. However, the ice charts and weather forecasts show more ice in the near future.

America steered the Polar Star, a U.S. Coast Guard Icebreaker, to rescue the ship because she was only 300 nautical miles (345 miles) away. She should reach the fishing boat on Friday or Saturday.

“The considerable geographic distances and extreme environmental conditions make this a complex rescue mission,” said Captain Matthew Walker, commanding officer of Polar Star. “However, we’re confident in our ability to reach the Antarctic Chieftain and committed to ensuring the safety of life at sea no matter the challenges.”

Polar Star is America’s only icebreaker capable of handling the thick Antarctic ice. Every year, the boat completes Operation Deep Freeze “to break a channel through the sea ice of McMurdo Sound in Antarctica to resupply and refuel the U.S. Antarctic Program’s McMurdo Station on Ross Island.” It was one of two ships sent to help a Russian ship in the same area last January.

“The seas of Antarctica are treacherous and unforgiving,” according to U.S. Coast Guard Vice Admiral Charles Ray. “This incident is a sobering reminder of the importance of the U.S. icebreaker fleet as we see increased human activity in the polar regions.”

America’s McMurdo Station is located in the sound, which is also Antarctica’s largest scientific base. It is very common for the thick ice to trap fishing boats that then need the help of massive icebreakers. The brutal cold weather makes the ice at least 9.8 feet thick.