SUPERIOR, WI (AP) -

Ships using Lake Superior are having a tough time due to the worst build up of ice in decades.

Wisconsin Public Radio News reports the National Weather Service started tracking freeze-ups in 1978, and says this is the second-fastest and thickest ice-up in 35 years. Coast Guard Soo Vessel Traffic Director Mark Gill says this is the worst since 1989.

On Friday, the Coast Guard said traffic was halted the four days before for several

Gill says a trip from Duluth, Minn. to Gary, Ind. that normally would take three days now takes six to seven.

Gill says many ships on the Great Lakes are tying up early for the winter. The Soo Locks close Wednesday.