Call them Army Surplus, call them eyesores, or call them cute, but those outsized amphibious vehicles so attractive to urban tour operators have an army of detractors.

Many of them are environmentalists who say the DUKWs (ducks for short) cause too much pollution, make too much noise, and pose safety problems.

In New York City, there's even a lawsuit involved.

Transportation Alternatives Inc., which promotes bicycling, walking, and even roller-skating as alternatives to gas-guzzling vehicles, seeks to stop Port Imperial Duck Charters from building a ramp into the Hudson River off West 38th Street, near the New York Waterway ferry terminal.

According to the lawsuit, Transportation Alternatives argues that the vehicles will pick up dirt, oil, and other contaminants that will be deposited into the river when the vehicle moves from road to water.

Another problem, according to the suit, is that DUKWs will cross the Greenway, a popular pedestrian path shared by bicycle riders, roller-skaters, and roller-bladers, more than a dozen times per hour.

The 50-passenger amphibious vehicles, also used in Baltimore, Boston, Philadelphia, and Washington, are former troop carriers refitted for civilian riders. The driver pushes a button to activate a propeller when the rubber-tired wooden craft takes the plunge from street to river.

Port Imperial Duck Charters has already acquired required permits from the New York State Department of Environmental Conservation and needs only one more, from the U.S. Army Corps of Engineers, to launch operations.

Company spokesman Pat Smith said many vehicles, including taxis and buses bringing passengers to the ferry terminal, already cross the Greenway without negative impact on the environment.