The crew of the U.S. Coast Guard Cutter Alder are getting ready for another bumpy ride, from Duluth Minn. to Thunder Bay, Ont.

The Alder is scheduled to start it's work breaking up the ice, to clear regional waterways in preparation for the beginning of the shipping season, on Thursday, and to arrive in Thunder Bay, on Monday. 

"The best way I can explain it is [it's like] being in a dryer," said Mark Gill, the director of vessel services for the U.S. Coast Guard, in Sault Ste. Marie, Michigan, describing the vibrations that rock an ice breaker, as it smashes through the icy water. 

"You're literally shaking your fillings loose ... it's kind of like mini-earthquakes." 

This year's journey may be slightly less bone rattling than normal, thanks to low ice cover on Lake Superior, said Gill. 

Watch U.S. Coast Guard Cutter Alder in action, between the twin ports of Duluth, Minn. and Superior, Wis. :

The Duluth-Superior ice breaking operations would usually begin about two weeks before the opening of the Soo Locks, on March 25, said Gill. However this year, the project is expected to take less time. 

"Because of the topsy turvy temperature flow that we've had this year, we've had ice develop and then go away and then develop and then go away."

"From an ice breaking standpoint, if you look at the port of Thunder Bay, you look at the port of Duluth, the St. Marys River, we have a little bit less [ice]."

"The coverage is there. But the thickness is not there," he said, noting that this winter presents a stark contrast to the deep freeze of 2014.

Great Lakes ice cover

A comparison of Great Lakes ice cover in February 2014 versus February 2017 shows a stark difference. (U.S. National Weather Service)

The Alder is expected to arrive in Thunder Bay, where several ships are already waiting to load with grain, on Monday morning, said Gill, and to spend about a day and a half clearing the harbour. 

The Coast Guard is reminding people to exercise caution on the ice, which is expected to break up quickly over the next few weeks.