Rockville officials are considering a proposed ban on reckless skateboarding, a move to increase public safety and reduce damage to private and public property.

"Skateboarders -- when they skate on marble, concrete and benches -- are just chipping away the material on public- and privately owned property," said city spokesman Neil H. Greenberger. "It's damaging and very hard to repair."

The proposal would ban the use of skateboards, roller skates, scooters, bicycles and unicycles in a "careless, inattentive or imprudent manner that endangers persons or property." Officials expect the measure to come before the City Council by the end of the summer.

Violators would be fined $400, and repeat offenders could have to pay as much as $1,000, Police Chief Terry Treschuk said. Police could also confiscate skateboards or bikes.

City officials say the cost of repairing the damage is significant, though they do not have exact figures. "Damage by skateboards is just not a line item in the budget," Greenberger said. Treschuk said that damage to private property is also extensive, resulting recently in $10,000 worth of repairs for one company that he declined to name.

Police say the majority of complaints are of skateboarders in front of the Regal Cinema on East Montgomery Avenue and the fountain at Courthouse Square in downtown Rockville. In addition to wearing away benches and steps, Treschuk said, the skaters often put wax or oil on public surfaces to help improve sliding.

City officials recently installed metal skating stops on the marble benches in Courthouse Square to make it impossible to smoothly skate across them. The next day, police said, the stops were gone.

"The skaters came with tools and removed them," said Burt Hall, the city's director of recreation and parks.

City officials say the property damage bothers Rockville residents. "When they start chipping off things and a person sits on a wooden bench that has been splintered, it's dangerous," Greenberger said.

Reckless bike riders also flummox passersby. Hall said cyclists sometimes frighten crowds on East Montgomery Avenue by riding fast. "We have kids going down that sidewalk cafe with tons of people at 20 miles an hour," he said. "That's nuts."

Hall said skateboarders should stay off public streets and head instead to designated skating parks. The city built a 10,300-square-foot skating area at Welsh Park, but older skaters tend to avoid it.

"Little kids go to the skate park, but no one I know goes," said avid skateboarder Jared Parr as two of his friends nodded in agreement.

Some Rockville teenagers say police have their priorities misplaced. "I think they should be going after real criminals instead of picking on kids," said Amanda McCullough, 16, who has friends who are skaters but is not one herself.

Parr, 17, said the proposed measure shows the city is more concerned with the appearance of public areas than the happiness of its teenagers.

"It's not going to work, and it's just going to make people more upset," he said. "Nobody is getting hurt by having people skate here."

He does concede, however, that a new ordinance would probably have some effect on skateboarding in Rockville.

"Skaters will probably run faster when they see cops," he said.