Joshua Brown, snuggled in an oversized coat and furry Russian hat, crunched along the ice-coated pier at the Columbia Island Marina and shook his head at the 15-foot high wooden pilings the ice and tides had lifted from the Potomac's bottom.

Brown, who said he usually spends his afternoons watching basketball games, was at the pier yesterday with dozens of other boat owners who were checking their cruisers for damage from the ice that has sunk some boats, damaged others and locked most of the vessels in place for weeks.

Some of the piling, poles to which the boats are secured with mooring lines, have been lifted from their muddy bottom and tilted as ice formed around the pilings and pushed them up with the incoming tide.

"The old times say its the worst they have seen in 30 years," said Tom E. Coleman, a rigger at Backyard Boats in Shady Side, Md.

Marina operators and boat owners throughout the area have been among the hardest hit victims of the intense cold that has frozen the country east of the Continental Divide this winter.

Several marinas report boats being pushed into piers by ice, or being tilted by ice forming underneath them. Some cruisers' cockpits have filled with foot-thick blocks of ice that must be chopped out with sledgehammers or cut out with chainsaws.

Some marina operators and many individual pier owners said their piers were raised several feet when the ice pushed pilings out of the river bottom.

"One wharf was lifted and titled about 30 degrees," said Doug J. Ashley, manager of the Shady Side Boat yard in Shady Side.

A pier at the Washington Sailing Marina was thrust upward about five feet when ice and rising tides pushed pilings up, according to Ronald R. Bates, assistant manager at the marina.

At the Columbia Island Marina about 30 pilings have "started to pop up a little," said William W. Hurley Jr., marina manager. The boats that onced rose and fell with the tide, are now locked in the 14-inch thick ice that shows swirls where the last tide seeped up and formed another glistening layer.

"It's crunched in pretty tight now," said Dan Sprague, an Alexandria boat owner who walked around on the fro-cruiser for damage.

The ice has also expanded the siding on some boats, allowing water seep inside and freeze. The ice has also knocked out caulking, which keeps the boat's planks together, Ashley said.

The water that has frozen in the boats' bottoms has caused some vessels to sink because pumps used to extract water from the boats have also frozen.

"We've had a lot of boats taking on water," said Garnar Hallmark, assistant manager of the Ft. McNair Yacht cally. We haven't had any go all the way to the bottom yet, but we had some almost there."

Coleman said "Watermen are out there every day chopping ice," away from the pilings and from the cockpits of the more than 150 boats stored on land. If the 10-inch thick ice is allowed to form in the cockpits, it could later seep into the boat's cabin and cause more serious damage, Coleman said.

The boat owners' biggest headaches may come when the ice thaws. Huge floating ice chunks may push boats into piers and crash into the sides of the cruisers. Increased water movement could force more pilings out of the water and boats that have been kept afloat by ice may sink, the dock operators said.

"We haven't seen the worst until the ice starts to move," said Dick Jablin, a yacht broker for Hartge Yacht Yard in Galesville, Md. "Something's going to give and I'm afraid it's going to be the docks and the boats."

The National Weather Service has predicted below freezing temperatures wil continue through next week.

A spokesman for Virginia Gov. Mills E. Godwin said three Coast Guard cutters are operating in the James RIver, the Lower Chesapeake Bay and in the Potomac River to help break up ice. The National Weather Service said Friday the James River is almost completely covered with ice from Richmond downstream.The average thickness of the ice is three to four inches.

In a weather-related incident, a Towson, Md. youth was killed early yesterday morning when his car skidded on ice and went off a road in the Woodlawn section of Baltimore County.