CLEVELAND -- The Coast Guard ice cutters have had a rough season on the Great Lakes.

The Ninth Coast Guard District cutters are still breaking ice and trying to maintain navigable waterways during the second toughest ice season in 11 years, officials said.

The Ninth Coast Guard District, responsible for the U.S. Great Lakes basin and St. Lawrence Seaway, employs eight multi-mission cutters to break ice in the region. The Canadian Coast Guard provides an additional four ice-breaking capable ships.

The cutters assisted nearly 150 vessels through ice more than 15 feet thick this season.

Five 140-foot Bay Class ice breaking tugs (Katmai Bay, Bristol Bay, Mobile Bay, Biscayne Bay and Neah Bay), are approaching 30 years of service. The extensive ice season, second only to 2003, creates an additional challenge for the Ninth District's Operation Spring Restore.

The district's buoy operation restores nearly 1,300 navigational aids to their assigned positions, including lighted and unlighted buoys and beacons. Operation Spring Restore has been delayed because of the ice season and will require increased cutter hours to meet the May 30 deadline.

"The Canadian Coast Guard assists with both operations, ice breaking and Spring Restore, but to complete Spring Restore in a safe and timely manner our (U.S. Coast Guard) cutters are going to have to work overtime," said Rear Adm. John E. Crowley, Jr., commander of the Ninth Coast Guard District.