GRAND FORKS (AP) - A Coast Guard unit that did rescue and patrol duty on the Gulf Coast after Hurricane Katrina is bunking at the Grand Forks Air Force Base and patrolling the Red River in flood rescue mode.

At least a dozen Coast Guard personnel manned three 20-foot Air Ranger iceboats in the flooded waters of the Red 20 miles north of Grand Forks on Friday. They are part of a contingent of 40 to 50 Coast Guard personnel who came to a spot as far away from a coast as any in North America.

Water, however, is plentiful as the flood of 2006 moves down the Red River Valley.

Even as the cavalry arrived, flood concerns were diminishing as the Red showed signs of settling back from crest levels.

The Red has widened out to several miles across in northeast North Dakota's Walsh and Pembina counties, giving the Coast Guard plenty of playing field. They arrived Wednesday, with the iceboats, which are dominated by a huge fan on the back powered by a 500-cubic-inch Chevy engine. They are similar to the airboats used in the Florida swamps, but tougher and more adaptable.

The iceboats handle whatever comes up along the Red, whether ice, snow, water, concrete or black mud, said Petty Officer 3rd Class Bill Colclough, spokesman for the Coast Guard unit.

One officer jokingly offered to jump North Dakota Highway 54 with one of the boats to demonstrate that little can stop them.

The Coast Guard unit is from the Sault Ste. Marie sector of the Coast Guard's 9th District, based in Detroit, with stations along the Great Lakes. The unit brought three 20-foot Air Ranger Iceboats, and smaller craft, to the Oslo area.

A separate Coast Guard unit from Traverse City, Mich. has two HH-65A Dolphin short-range recovery helicopters running reconnaissance missions up and down the Red River, Colclough said. The same Coast Guard personnel and boats were used in even bigger numbers last year in rescue operations after Hurricane Katrina in Louisiana and Mississippi.

Friday, an Air Ranger iceboat was used to deliver nitroglycerine pills to an elderly woman with a heart condition in rural home north of Oslo, cut off by floodwaters, Colclough said.

On Thursday, an electrical generator was delivered to a farmer north of Oslo who is hemmed in by water, he said.

The Coast Guard units are on call 24 hours a day for anyone needing help, he said. Citizens can call their local 911 dispatch centers or local emergency operations center and ask for help.